Man, this makes me a little worried.
You clearly went RB heavy in the draft leaving your WR a little thin. If you give up Cooper, who is considered a strong upside pick this year, you’re left with the following:
Robinson - Coming off injury, new QB, Role assumed WR but unknown Run/Pass attack balance
Williams - Receiving option 4 on his team? Considering a TD dependent sleeper. Antonio Gates resigning HURTS
Edelman - Good stuff, but no action till week 5… good pick
Anderson - Big Play Machine with a starting rookie QB, scary!
Locket - Honestly, kind of like Anderson but with a higher floor I think? Outlook cloudy
While Gronk is great, if you can get a Doyle/Njoku/ASJ/OJ How… I feel like you gotta take the flyer.
That said, you most definitely can part with some of your RB depth if you need to. Not sure your league construction but assuming you can play max 3 RB’s.