The Broncos don't need to get Roberts more involved at all.
Look at Latrell, he had 7 runs on the weekend and had 3 tries & 2 try assists, Roberts had 11 runs on the weekend for literally nothing. Roberts needs to do more with the touches he does get, and also needs to go looking for more work, like Oates does.
We have these niche plays that have Oates ending up on the right side of the field running off Milford short balls, we allow Bird the freedom to run literally whenever and wherever he wants, sometimes ending up on the opposite side of the field for a couple of plays. Are you telling me that Jimmy doesn't have this option available to him? The only reason he's stuck on the right edge and "not getting enough ball" is because he's the laziest fast person I know.