I haven't mentioned Josh specifically but I agree he is also really good. If you count his receiving yards he has the highest YPT (Yards per Touch) of the RB's at 8.7 and he averages 7.0 YPC on pure rushes.I rarely offer criticism of CNS/staff for various reasons, the only exception to date has been regarding personnel. IMO, there are those who should see more playing time: Ray, Moses, Williams on D and Damien on O, maybe Wills for Womack. I do think JJ is closer to DH than you say. Also, to be fair to the staff, last year DH did wear out toward the end of the year. Some of it was nagging injuries, some may have been fatigue. In the end I realize there are likely factors of which I'm unaware, but looking on the surface, I agree wholeheartedly with your thoughts about DH.
If Damien had to miss some extended time I'd be looking between Josh and Najee to take his snaps with the edge going to Josh on production and experience.
I'm not trying to disparage #9 at all either. He is very valuable and I understand he's not even close to 100%. He's a warrior....I love the guy. But for right now jmho he should be in a limited specialist role. His mobility is limited to North/South running right now.
In space he can for sure get some yards with a head of steam on swing passes etc and he's GREAT for short 3rd-4th down and Goal-line situations and/or giving Damien a breather. If the OL gives him an actual hole it's going to be a big gain no doubt.
But our OL is not doing very well at opening holes for North/South running right now. I think Damien is the best RB overall no matter the blocking but he's especially the best at Cut-Backs.....by a wide margin....and that's what we need until future OL improvement/consistency is established.