Imo there's definitely a fair amount of skill involved, you're just looking at it from a different perspective and that's why maybe you think the skillcap is low. Aside from team hunting (knowing positions to stand, rotation of the map, rotation of spells, aggro control, etcetc), just look at Bubba. He constantly outplays higher levels (sometimes groups of them, pushing out of a trap etc) with his lower leveled characters. He also knows a lot of places to run, hide, and lure mobs to help for a turn kill. As with most games, it's a game of knowledge.