You aren't running the ball for 1st downs with Charbs. You can pass to him for it, and he can even catch the ball and run for it ala Jon L Williams for big gains.
But he is far too slow to take advantage of any holes your line makes for you. He's getting you 3 yds or under, but at least 1-2 for sure. You don't run for 1st downs with that. He makes DJ Dallas look quick by comparison.
If we want to score, we have to pass our way into the EZ. or at least pass our way to within the 5.
OK 4th and 1 is the time to use him though....