Love the starting backline, HATE the bench sans Tate. I can hear an argument for Ben over JOC (James O'Connor) just based on familiarity with the squad and overall pep, but I'd prefer JOC (James O'Connor) based on the sheer number of positions he can cover that I'd feel just fine about him covering. I think Kellaway is the biggest waste of a spot. He hasnt been playing particularly well, and he's most likely in there to cover more positions.
If you pick JOC (James O'Connor), that theoretically goes away and you can give the other bench spot to a spark plug who can break the game open against tired legs in the back end of the second half. I'd be much more inclined to throw Corey Toole, Dylan Pietsch or Hunter Paisami that spot (granted there is coverage issues with each of them).
In fairness, the current make up gives you the most coverage if something catastrophic happens in the starting side, but I think you have to play some sort of risk/upside game here...
Also Lynagh is an animal and he's made for this, I back him 1000% without any hesitation.