I like Barthel too & I think he'll develop into a very good RB coach. His issue right now is he's hitting the south hard but he has no natural ties there.
He is targeting HS RBs in places like TX, FL, SC, etc...and Barthel is from the northeast. Take the Kewan Lacy recruitment as an example: Garrett McGuire was crucial to getting that commitment (bc he speaks fluent Dallas Metroplex-ese). I don't think Barthel could have gotten that far with Lacy on his own, just due to not knowing the TX lay of the land like McGuire does.
So that's the issue with Barthel right now. All these RBs are from the sun belt and he's not. He can build up ties to three places it will just take time. When you're a new staff, the natural ties mean everything - look at Donnie Raiola: closed on Ben Scott (Honolulu), closed on Preston Taumua (Honolulu area), making progress w several Poly OL recruits in UT/NV/CA.
Barthel just doesn't have a natural 'in' right now w the places he's being asked to recruit. But he does have playing time to offer though and that can go a long way.