[iRFNA]

I'd say your problem is that you're sending thugs against forces too great for them to handle. Ya, stating the obvious, but perhaps you should be using it to harass and kill smaller armies, or send it into battle with an army and/or mages at its back?

The problem with, say, gargoyles is that they have a few weaknesses: they are magic beings and inanimate. The inanimate is especially bad because they can be blown apart by shatter and there is no save. Gotta watch out for the same thing with undead, although different spells.

One way to deal with obsessive vining is quickness, since it gives your guy a chance to break the vines then still attack, rather than being deadlocked.

Mages are always going to have a counter of some kind to anything you can make (assuming your enemy has the right paths). There's really no getting around it. Find a way to kill the mages, fight when they aren't around, or make sure exploiting your weaknesses requires magic they don't have!