@MOFO
Yes, normal unit size only. Theoretically, there is a workaround for large unit sizes if you use it as a general's bodyguard, but this workaround lead to results worse than what we have now. Also, it would mean the Hero units could not be used in custom battles - and I guess that's not really what you guys want.

@Alexander
Nope. It will definitely crush all your beloved vanilla files.