I've only been van mounted for a few weeks, so still very much a noob; but I find I have to take our hose reels out of the van and point them in different directions for us to work.
I'll go left to work on one house, Wor Lass goes right to work on another; that sort of thing; hence I always lift the reels out and point them in different directions. So - at present - I don't know how you guys work with fixed reels.
And with that set up shown in the pic, if both of you finish at the same time, only one person can reel the hose in at one time. Both guys couldn't reel in at the same time otherwise you'd end up looking like you're playing a strange version of Twister.