WARNING: The following contains spoilers for My Hero Academia Chapter 345, "Division,” by Kohei Horikoshi, Caleb Cook and John Hunt, available now in English from Viz Media.
While All For One and the villains returned to the shadows, All Might and the rest of the Pro Heroes were hard at work formulating a plan of engagement toward My Hero Academia's most climatic battle yet. They've settled on separating the villains and crushing them individually. It's no wonder All For One commended this strategy, as it was almost the same as the one his protégé, Shigaraki Tomura, used much earlier in the story.
Class 1-A's first encounter with villains occurred when they traveled to an outside facility for a special lesson. The Unforeseen Simulation Joint, or USJ, was a special facility isolated from UA's main grounds that students visited to prepare for hero work in adverse environments. The facility had several different biomes within it, each with a specific disaster theme that the heroes in training could gain experience from.
More recently, My Hero Academia revealed that Aoyama Yuga, the UA traitor, tipped the villains off to Class 1-A’s location. They planned to kill All Might and, as soon as they arrived via Warp Gate, teleported the students to various parts of USJ. It was a divide and conquer strategy that aimed to isolate All Might with the High-End Nomu Shigaraki brought while leaving the students to the lower-level villains who escorted them.
All Might's plan for the upcoming war is almost a carbon copy of the strategy the League of Villains used at USJ, all the way down to some specific elements. Both plans could only succeed with a teleportation Quirk, and it just so happened that both teams used the same one: Warp Gate. Aoyama also acted as a mole for both sides, allowing the villains to see All Might's schedule, then later baiting them into mobilizing to steal One For All.
As soon as both teams arrived at their ambush points, their first order of business was to separate their adversaries. The UA students were scattered around USJ while the villains were tossed to various locations all around Japan. The villains could afford to leave the students there because their main focus was isolating All Might, but Monoma Neito was forced to push the boundaries of Warp Gate as the heroes' plan hinged on separating All For One from Shigaraki.
Both of MHA's iterations of this Warp Gate-centric plan worked marvelously, but the villains' idea failed because they didn't anticipate that 1-A could regroup so quickly. Seeing as the heroes have taken all measures to prevent the villains from reuniting, their plan seems more likely to succeed -- but they're not out of the woods yet. All For One is nothing if not tenacious, and his vast number of Quirks means the heroes still don't fully understand what they're up against as My Hero Academia continues.
