High-sec wars are now exclusively an N+1 game. There’s absolutely no room for any kind of maneuvering or asymmetrical warfare. The bigger group is simply able to force a fight at a structure, either destroying assets to force the surrender/destruction of the smaller group, or destroying an enemy’s war HQ (within a day, maximum two days if it’s a large structure) to forcefully end the wars of any smaller group. CCP crafted this new system with specific intent, because their goal was to reduce the overall amount of wars in high-sec (which the new developers consider to be grief-play and wish they were never in the game to begin with), which has been a successful effort if you look at just how few wars get declared on average these days.
In null-sec, a larger group can destroy a smaller group’s structure(s), but that in itself doesn’t completely end armed conflict, because the smaller group is still able to engage in combat. In high-sec, that’s simply not possible, because your ability to declare war goes into a two-week cooldown period when you lose your HQ.
Basically, in an effort to fix the problem of high-sec mercenary groups balling up into large, unbeatable blobs that blanket-dec everything around them, CCP created a system in which the only way to survive as a high-sec mercenary group is to ball up into a large, unbeatable blob that blanket-decs everything around it. Kind of similar to how CCP is “fixing” ganking right now with the intent of deterring gankers from ganking younger, easier targets by severely restricting the ability to gank anything that’s not a younger, easier target.
They don’t play their own game.