There is no harder Mode than Tactician, Honour Mode is Tactician as Ironman mode, it is not harder, you just need to puzzle even more, because you can't just reload if a fight goes downhill.
Regarding 'rewards': Getting together Bracchus armor just to then sell it, because its stats are underwhelming is just another example of how unrewarding the game often times feels. But same goes for experience: A hard fight often yields less experience than a cheap mass fight like the voidlings ambush.
