This fight is already a chore as it is. And what makes it so is the design choice of spamming enemy units in large numbers. Improving the allied ai would at least make it go quicker, since they would get better at disposing of the enemies themselves.
As for rtwp, I've used web and pit spells in this fight. No idea why you think it is not feasible. It doesn't really matter if some of the allied units run into them, they don't care.
