Dude, Chuba hasn't even been in on the regular this season, but we know what he can do because we've seen it already. Dowdle isn't built to be an RB1. Sure, he's been productive, but his stats were passed against some sketchy run defenses. I told someone earlier this season that Chuba could have done it just as well, but of course this is dependent upon him being healthy.
If you're suggesting that Dowdle was almost as good as Chuba today, then that's not true. Chuba was the better back today, and he's the better back over time.