you do the trade no matter what. Between marshall and stewart, it depends on if you need a WR or RB more. Marshall will play every week, although his offense sucks he will still get some points. stewart is going to get very little points most weeks and is really only a gamble play hoping for a big reception or a TD. But if you need a RB real bad, he is worth the gamble I think. He could be top 10 if he became the starter somehow.