Help on Red Brotherhood lair?

So I finally got the RB lair location from a traveler, at about day 300 and level 30. I thought me and the team was the dog's bollocks, but apparently the level scaling on these lair quests is insane. I have the best troops, bar the noldor: Hero adventurers + Barclay sappers, and of course high level (archer) companions in plate. Apparently this won't do though, and I need some specific advice.

My team kills the ~20+ enemies at the lower hut and the hillsides rather easily. The distance is great enough, though, that if my companions shoot, we're pretty much out of arrows at that point. During this fight ~10 enemies gang up at the cave mouth, including the Singalian Wonderwomen. The next stage of the fight is on when I prod the group by shooting one of them, and they charge. I have beaten this rush a couple times, but more keep on spawning while killing them. Seemingly always resulting in my group getting either surrounded and outnumbered, or running out of ammo.

I'm using a xbow and sword+board btw. The accuracy of the siege xbow is also not what I expected. Is sniping with a bow the only way to beat this thing?

Submitted September 25, 2017 at 04:06AM by teemul http://ift.tt/2wQEZw6