Bennett isn't a RB. He most certainly isn't a LB.
Even Tosin who is a good player, is not improving. Right here and now, he is going backwards.
For his own progression, he would be best off leaving now, before the end of the season. I'd let him go, the players have given up, as has the manager.

I can name half a dozen footballers who are all going backwards, Rothwell, SG, Samuel, Holtby etc etc.
Tyhe biggest factor is, in the last 12 mon ths this football side have no improved, at all. That's not good enough.