I don't actually know anything about Procreate, I'm just throwing out tools that are usually common in most digital art apps. If smudge is a bit too violent blur might help you. Of course the other problem is all the apps seem to handle the same tools slightly differently XD
Oh haha I was doubting myself already missing something. Smudge seems good for more rough paint styles but I see artist use it for smooth gradients. Probably a workflow that doesn’t really work for me. That’s true they all seem to work a bit different :)