Trade offer: Ajayi for Mixon

I’ve been offered Ajayi in a 4 player keeper league, standard scoring. On paper it looks like a no brainer but I can’t get away from Mixon’s upside going forward whereas Ajayi has been up and down. My other RBs are McCoy, Gordon and Hyde so i don’t feel like I HAVE to make this trade. I’m just not sure.