I find heroes a bit useless cause they just don´t have enough strenght to kill a single thing at least in suicides, I don´t have problems to get very high melee, endu or/and armor with hero gear, but capping their strengh is nearly impossible because they can´t wear banners, I give a few suggestions there.
1. Use banner frags but not to craft banner for heroes, but instead craft decorative clothes, like mantles, tunics etc. that don´t offer any protection but instead increase strenght.
2. Share the unit banner strengh, the hero still can´t wear banners but is the unit they are commanding have a banner equipped, they will receive the strenght bonus as well.
3. Greatly increase their base strengh.