How about a "support" hero? He's not going to do a lot of fighting on his own, but he's great to bring with your troops.
Combine any (or all) of the following:
- Supply bonus
- Standard
- Healer
- #onebattlespell a cool troop buff
- Summon Allies
- #domsummon
Many of these ideas have already been suggested, but not all of them. My point is to tie them together into a hero who should be out-and-about with your armies even though he isn't a Thug or SC in his own right.