I have another suggestion: keep a couple of maps of these new ones, and put back in the rotation the old maps, EXCEPT the exploitable ones - Yaragar, Istiniar, Rizi,... (all those with fences, elevated haystack, roof access, etc.).
I appreciate your work with the maps, Fips, but with 30 player limit, some of them are too small. The problem, in my opinion, is that people would rather go "ezmode", make a shieldwall at the small gate, and don't care about 1/3 of the team getting bored / leeching, than letting the bots inside the castle so everyone could fight. We can always blame the map, but every map can be played in many ways.
Still, I think that combining some of the old maps with the new ones and, if possibly, enlarging the access points so more people can fight, would be great.
OR give a percentage of bots in ALL waves a great maul and str build. That way shieldwall might not be unbreakable anymore.