I could see 6 targets a game. 6 receptions, to me, is tough.
Using
@cloppbeast's "reasonable" 30% decrease, let's run the numbers:
Let's say Brown has 20 attempts this season (23 less than 18, those go to DH)
Henderson gets all of CJs attempts (43) and Kelly's attempts (12)
30% of Gurleys load is 77 carries.
Total: 155 carries (Gurley with 179, so a 50/44/6% split with Gurley, Henderson, Brown... a bit different than
@dkp993's prediction of a split. interesting, what's "reasonable" to one Henderson critic "doesnt make sense" to the other)
now targets:
Kelly, Brown, CJ combined for a measly 16, let's give those to DH
30% decrease for Gurley means 57 targets, so 24 to DH
Total: 40 targets
Personally, I think Henderson gets more than 2.5 targets per game, and I think those targets come from the WRs mostly as you have said (RBs more involved in the passing game), but if we are going to strictly stick to RB volume from 2018, based on Clopps own "reasonable" volume decrease, this is what we come up with.
I'd gladly take this as his floor