Ideas and suggestions.

Any stack with 10 attack speed/retaliation takes a tier 1 building with a single unit, which is overpowered and needs to be fixed.
P.S. 7 harpies take the highest tier building on a map with 9 speed, neither with lore nor on their native land, which also needs to be fixed because it's overpowered.

1-50 harpies taking a building is not normal. Any number of fairies, etc.
Flying units also take buildings at 9 speed, it seems.

Fixing the single-unit timer limit will address this. Stacks with more units won't, but it should. Hopefully, Sav will see that many people share this opinion.
Nodl's suggestion to make it 6 stacks fits the concept of HotA, I think.