I have considered trying to move gronk in this league but the teams that are in trouble at the TE position aren’t willing to give what he is really worth.
This is tough, but yeah, you should probably keep all those guys. Plus, the fact that no one who needs a TE has opted to pick Kittle up yet shows what he’s worth in your league at this moment. I’d also have a tough time with him just sitting there like you are, though. Keep a close eye on the situation obviously.