Ghosts are only good vs living units, 7 battles with ghosts against undead is gonna leave you without any ghosts.

I'd use royal snakes, especially if you've got fenora, + snake ring, or + poison damage. Putting blind on 500 skel archers is a good thing, as you prob can't fireball them away completely. Snakes are resurrectable too.

My warrior was pretty beefed up with leadership, I think it was around ?4000? when I did abandoned castle.

I have to disagree, in general, about Cursed Ghost vs undead. With the right spell support they do excellent target against undead army. I show various snapshots of them with target against non living army in later game.

But I agree in this case, because I haven't yet the right spell support and the strength difference is too high so it takes too much time to kill stacks. In this fight I mentioned 12 units lost for the whole army isn't a lot for such fight. But that's a lot for an initial stack of 25 Cursed Ghost.

And yes I need use a different approach, probably without cursed ghost, more based on res and Royal Snake even if I don't have items you mention. And I'll pick up blind too. :)