Depends on the team.
One of mine with Dobbins is 3-2 and is the current high scorer - I have M Sanders, J Conner, J Robinson, A Gibson, and Dobbins. I can afford to be patient, so I'm finding out if Dobbins' role expands post bye with him stashed.
I have another team that is 4-1 and also the high scorer. BUT...my RB's are Zeke, Edmonds, Akers, and Chubb (IR). Hypothetically speaking, should both become available next week what I do likely depends on a win or loss this week. And if my place in the standings were worse then I absolutely would prioritize Kelley.
The objective is to have the best team come December, but you have to get there first.