Make the base calculation of the modifier enemy troops killed * your troops survived. So a splat gives you nothing. Enemies dodging gives you nothing (unless it's a treasury, and then you get treasures and possibly VPs depending on alliance/kingdom standing). Well timed follow homes, especially cav on clubs, returns a motza. Picking the right target and killing a reasonable amount of def for minimal losses to your hammer returns an absolute bonanza. Alternatively, make it enemy troops killed/your troop losses - similar sort of return, the more troops you kill for minimal losses, the bigger modifier boost you get. If that modifier keeps increasing with every successful attack, an alliance that doesn't have huge treasures but chooses their targets wisely and attacks heavily could still outperform the sort of meta simtastic alliances that tend to dominate servers as it stands - especially if you scale the battle calculations for relative size.
To bring this down to a single, shortish paragraph for the tl:dr modern generation... I don't think you need to dream up new mechanics - I think the basics of TK is a massive improvement on TL. You need to tweak VPs to reward attacks, you need to fix the imbalance towards def (and I get you're after a slice of the casual gaming market, so no huge consequences, but you've overloaded def with the hero bonus and items), and you need to tweak battle calcs and reins/diplomacy to allow for other strategies than meta for a server win.
This is excellent. Do this.