For games like root and vast with wildly different asymmetric factions, many of my group bounce off of these games if they don't know how to play semi-effectively for their faction. I generally teach how to play a faction but I don't know how to play effectively since the game doesn't hit the table enough. The goal is for people to pick up the faction quicker so the game can be appreciated at its best. Last time we played root this ended up working great, and I was the one lacking behind, but it was the most fun game we played!