I'm also in the "we still have stuff to play for" camp. Get a real LB in and this team, provided our CBs don't go to hell, and we can play with anyone outside of the top 6. And even them on a bad day.
Now my assumption is that Tosun is a marked improvement and that Walcott is effective opposite of Bolaisse. We'd be even better with a midfield engine like Doucoure to jump start our transitions, but if we got Tosun, Walcott, and a LB that was decent, I'll be pretty happy. Still doesn't make us great, but better than everyone else with the possible exception of LCFC.