Seriously, just cutting the player numbers down would help Frontline a lot. As long as there's lots of players in each team they pretty much have to balance around people just moving as death ball (well not neccesarily but we saw what happened with the mass summoner early on since everyone wanted to keep stacking up instead of splitting to smaller teams).

Too many players -> additional damage reductions -> can't have small skirmishes -> everything relies on coordinated mass AoE.

If they really want to keep on having big teams, they might have to reconsider map design. Making multiple spawn points per team and spread objectives so far apart that it forces teams to split up to cover everything or they just end up straight up losing since they can't cover enough ground with one big blob.