The Bane Lord vs devil/tartarian squad battle, IMO, really only worked well for you because of the storm that grounded my flying Bane Lords (and I started them from the back...) - Half of them did not get into battle at all before they all routed...
I think it would have gone in my favor if not for the storm, as I would 5-7 Bane Lords per devil/tartarian.
I think I had 55 total leaders, of which 42 perished foolishly!
Well I am not sure it would have gone so well for you. With the wrathful skies doing constant damage, I think my SCs (which had good prot and excellent defence stats) would have held their own. Of course, with the turn archives available, one can always test that theory!