Dynasty League Trade Offer

So I have Chris Carson, but I’m worried about his fumbling issues so I wanna get Rashaad Penny as a safety valve just in case something happens with Carson.

Should I offer this trade? Is it even fair?

I receive:
Rashaad Penny
Mecole Hardman
2020 6th round pick

They receive:
Raheem Mostert
Brandin Cooks
2020 3rd round pick

I don’t want to offer it until I get advice on whether or not it’s a fair trade. I don’t want to get ripped off and I don’t want to send a bad offer.

Any thoughts?