Make “buildings” hitting creeps remove xp gained from that creep by a %. Ex 1 hit, 50% xp less gained when the creep is killed by that player. Each hit multiplicative. NE will still be able to creep with AOW but will have to only tank dmg with it. Slows down NE creeping a bit. Also less burrow exploit by orc on ex twisted meadows.
Make mountain giants have an aura that makes them take a % of the damage from the friendly units around it. Making them soak some dmg. The aura small enough for it to matter to have a a few MG’s to cover your army and to be chewed through first. Also, make them fortified armor to make more interesting unit compositions to counter them. Like demos, glaives, mortars etc. And make them targetable by tanks.