Well, key to win is to not rush your leader into it. Take control of leader, two orcs (peons), two demons (towers) And a few orcs to be able to move the demons only. Stay out of fires with the healers obviously but all you do with them is healing, dont move otherwise. Start killing off the other teams healers with the two orcs and two towers, heal constantly when cd is up. When their healers are down or close to dead, start moving your leader to their leader. When you start dpsing their healer, keep healing your leader.

It's not easy, but the skills all have considerable cooldowns. I multibox 4 on chess myself sometimes and it is very doable to do 4, I'm sure 5-6 should be as well. You just need to get the feel of the cd's a bit so you know when to swap to which char to control.