Justice is a fan-made global mod.

No, you can't. The incorporeality coefficient is General for all incorporeal creatures, and I wouldn't advise changing it, because the rule "cannot have 3 hits or 3 misses in a row" will still work, but it will only confuse the player.
Having very low HP doesn't mean you don't want to lower it; you can simply give them a super ability that raises their HP by 2 levels (almost doubling it).

I think the Warriors have been nerfed too much, especially since the Archers have been buffed. They have different roles; the Warriors played well in the final stages, but the Archers were needed for dealing damage. Now, the Warriors have no place in the Necropolis army; stopping arrows are decisive. They need to at least keep the large shield (but the defense can be lowered).