According to the packets sent back by the Jackals, the protagonist notices that the tactics of the Northern Expeditionary Force have changed dramatically, or improved.

In the past, there was no difference between the tactics of the big-headed ant kingdom army and the paving ant barbarian army, with squads and squads, legions and legions, arranging a straight and deep battle line to attack each other. The side with more ants can rely on extending the length of the battle line to gain an advantage on the outside line, and the thickness determines the defense and long-lasting combat ability of the entire front.

Some legions will have the personality traits of the clan commander, but they will also play a role in the length or thickness of the battle line. Brave commanders prefer longer and thinner formations, hoping to establish an advantage as quickly as possible; A prudent commander will increase the thickness of the battle line, ensuring that the corps is not prone to collapse.

For thousands of years, the pattern of warfare seems to have changed little.

Until the protagonist came to this era, in the first year of the Reconquista War, the protagonist was keenly aware of the rigidity and disadvantages of the ants' plane tactics, and little by little in actual combat, he perfected the three-dimensional "razor tactics" that the Divine King's army has used to this day.

Some other intelligent and sensitive kings were quickly inspired, such as the public security kings and the western kings, who were friendly with the protagonists at the time, and adjusted the tactics of their own legions.

However, since these kings themselves did not understand the concept of three-dimensional space, the only result of their blind imitation was to learn to use the soldier ants in the legion intensively.

Although these kings can't turn all the troops under their command into soldier ants like the protagonist, this small adjustment of concentrating on the soldier ants brings a great tactical advantage. This is a disguised slash tactic that uses local superiority to achieve overall superiority.

Diagonal tactics, also known as diagonal formations and trapezoidal formations, are formations in which the army is fought in a diagonal formation, with a right oblique formation before the left to the right and a left oblique formation before the right to the left. Its essence is the unequal distribution of forces and the concentration of superior forces.

In the Battle of Leuctra under the command of the famous Theban general Epaminonda in ancient Greece, the enemy Spartan troops were stronger than the Theban army, and they were more numerous, and were able to discharge thicker formations.

In view of the general and evenly distributed forces of the Greek world's heavy infantry phalanx at that time, Ibamida abandoned the attempt to discharge the same length as Sparta, but concentrated his forces on one flank, and instead increased the number of columns on the left flank, from the traditional eight to twelve columns to fifty columns, in an effort to achieve a breakthrough.

But there is strength and weakness, and if the strengthened side of oneself wins, and the weakened side is broken by the opponent, it still makes no sense. Therefore, in order to protect its weakened wing, it was retracted and the battle was delayed, and its reinforced left wing rushed towards the Spartan army at double speed, hoping that the strengthened wing would make a decisive breakthrough.

In this battle, he defeated the elite Spartan troops, who were said to have "never been defeated in the same number", using slash tactics, shattering the myth of the invincibility of the Spartans and ousting the latter from the position of Greek overlord.

Later, starting with King Gustav II of Sweden, in order to fully exert their firepower, European armies adopted horizontal formations (i.e., line tactics), which was greatly enhanced, but there were also disadvantages of dispersed use of troops. In order to develop firepower, a horizontal formation is necessary, but how to maximize the concentration of forces while maintaining a horizontal formation? Frederick the Great of Prussia then "reinvented" the diagonal formation of Epaminonda, applied it to the battlefield, and achieved brilliant results in the Battle of Saul and the Battle of Rossbach, making this formation famous all over the world, and many countries imitated it.

The slash formation has been one of the basic formations of the army until the 21st century, especially for armored units, fighters, etc., which shows its excellence.

The slash formation variant of the soldier ant concentration tactics that they imitated did not become popular in the country of the big-headed ant king at first. Until the establishment of the Northern Expeditionary Army and the adjustment of the elite troops of the Big-headed Ant Kingdom, no more than five legions had mastered this tactic.

During the entire Northern Expedition campaign, the two sides of the big-headed ant kingdom and the paving ant barbarian kingdom were still engaged in a traditional duel, and only five legions that mastered new tactics were not enough to change the pattern of war.

But this time, in the information packet, although due to the lack of troops of the paving ant barbarian army, they rarely saw a decisive battle on the ground. But judging from the formation of the Northern Expeditionary Army when it was assembled, their tactics had greatly improved.

Most of the legions have already formed the soldiers separately and placed them on the side of the first line of the entire legion to form an assault force. This is precisely the typical characteristic of the tactics of concentrating soldiers and ants mastered by the public security kings and others.

Not only is this tactic popularized, but the protagonist also notices that the proportion of soldier ants in individual legions has increased significantly, although it has not yet reached the proportion of pure soldier ants like the Divine Envoy King Legion, but it is also far higher than the proportion of traditional soldier ants accounting for only one-tenth, and the highest has reached one-third.

The protagonist feels that the Northern Expeditionary Army is trying to use the powerful Divine Envoy King Legion as a template, and the easiest thing to start with is naturally to increase the proportion of soldier ants.

He didn't quite understand why the Northern Expeditionary Army began to innovate rapidly in just one winter and half a spring, and completed the tactical and organizational changes that had not been seen by the Big-headed Ant Kingdom Army for thousands of years.

But obviously, the combat effectiveness of the Divine Envoy King Legion is in the forefront, and a traitor like Da Rong can pass on the information such as the establishment and tactics of the Divine Envoy King Legion, and it is not difficult for the Northern Expeditionary Army to imitate it.

But the core "razor tactics" of the Divine King Army, the protagonist doesn't think that the Northern Expeditionary Army can learn it.

The core of mastering "razor tactics" is that the corps commander has three-dimensional thinking and can understand three-dimensional space, so that he can command his troops to make appropriate tactical movements.

Most males are only able to understand this concept before and after the wedding flight, and gradually forget it as the wedding flight is over and loses its wings. Just like many students who can't solve algebraic geometry problems after a few years after the college entrance examination.

Therefore, the commanders under the command of the protagonist, from the beginning of the roll to the later mantis tiger, etc., are relatively young, and they are in charge of the troops not long after the end of the wedding flight, and they continue to practice and consolidate this concept, so as not to lose their perception of three-dimensional space, and to be able to use this tactic correctly.

However, the commanders of the Big-Headed Ant Kingdom are generally senior, and the commanders of the legions are often older males, who have long since degenerated into completely two-dimensional creatures. Such a commander, even if he had a full set of tactical information packages for the Divine Envoy King Legion, would not be able to lead his troops to use the "razor tactic".

Since the Northern Expeditionary Army is not yet a threat to themselves, it doesn't matter that the protagonist popularizes the tactic of using soldiers intensively.