If it were up to me I would change the following:
Standardise similar rules.
Being able to generalise how things work makes it easier to remember.
“All situational advantages give an extra d8”, for example.
Separating the combat mechanic from situational advantages should be fine though.
I hit with my Me stat (minus your special rule), plus d8(s)for clever thing I did (like supporting model).
I wound/you save against De stat (minus your special rule), plus d8(s) for clever thing (like making you cross terrain).
Preferably always add rather than remove dice.
From that: bracing or any kind of defensive position gives an extra d8 for saves as well as denying an extra d8 for shooting in the open (but not melee).
Replace the knock down mechanic with a nerve test similar to KoW.
We’re already tracking wounds, so one less thing to keep track of.
Also means that the try and try again to kill something potential NPE (IMO) is eliminated. Tubthumping enemies are incredibly frustrating. With an Ne system you get closer at least.
Having it quite swingy is great though, so a d8+damage vs Ne stat. 1 always passes and 8 gives a fatigue, maybe?
Can give similar odds. Ne 2 means that any damage needs a 1 to survive (give grunts a chance!). Ne 7 means that a model that takes 2 damage has a 50% chance (as is the case with 2 wound models now) but a very slim chance of going down from 1 damage. Ne of more than 8 for large models never go down in one hit.
Speaking of swingy being fun: DEFINITELY KEEP EXPLODING 8’S!
I would drop, or at least limit, power. It feels “gamey” (i.e. anti-immersive) and randomly disadvantages warbands that need it on some turns. Plus it’s a layer of complexity in a game with too many.
Maybe a set number of heroic actions per turn, as mentioned above?
The same resource management can be done using activations and fatigue. Special warband abilities might as well be “once per turn”.
I really like the fatigue mechanic; the thematic image of a warrior desperately pushing themselves… just… a… little… more… is great. Borrowing from the future is an interesting and risky choice.
Power seems popular and fatigue is something to keep track to though. The argument can certainly be made that it’s better to dump fatigue in favour of power despite my preference.
Either way, I would definitely choose one over the other.
Drop the restriction on taking the same action twice.
Means actions can have an action cost (which might come from fatigue/power) and no need for long action rules.
Charge then becomes a move and attack for an action. If a model is far or wants to move around an obstacle then it doesn’t get as many attacks when it gets there.
Rear arcs, group moves and retaliation are cool, but I’m not sure the extra rules complexity is worth it.
I would dump warband morale, a bloody struggle to the end sounds more like it.
A cap on duplicates and/or warband size mould probably be necessary to limit activation spam though.
Having cheap stuff die easy to models that can attack more than once a turn might help though.