It's a RBBC.
Whatever happened earlier in the season is not relevant. The last 3 games they were both healthy is all that matters. It's not about what was, it's what is and what will be.
Week 8:
Charb: 5 rushes, 2 targets
Walker: 8 rushes, 2 targets
Charbs leads snap count 59% to 41%, Walker win touch(target) battle 10 to 7.
Week 9:
Charb: 4 rushes, 1 target
Walker: 9 rushes, 2 targets
Charbs leads snap counts 55% to 49%, Walker wins touch battle 11 to 5.
Week 10:
Charb: 6 rushes, 5 targets
Walker: 19 rushes, 2 targets
Charb wins snap count 52% to 48%, Walker wins touch battle 21 to 11.
Totality of all 3 games has Charbs outsnapping him each game and Walker winning touch batttle 42 to 23.
To me, even I ignore the coach saying he wants to give Charbs the ball more then Walker in some games, that's a RBBC. Walkers the primary runner and rushing attempts are going to generally exceed RB passing game targets in this offense. It all seems overly simplistic to me to think it needs to be a near even split in touches to be considered a RBBC. I have never understood or felt a RBBC meant something close to dead even touches. It means one RB is not a bell cow because one or more RBs' are putting a massive dent in their usage. This is NOT a pro-Charbs post.