If the season started tomorrow (i am told it doesnt, still checking on this) the backup 4 is Hart. I think that is fine in spots, but I don't love the idea of going into the season with that as the plan. If Randle misses any time you run into some serious issues. But if you're going to have redundancies anywhere, you want it to be with versatile wings who can shoot.
I think there's a consolidation trade coming. The Paul George thing probably isn't happening. But if you did something with OG coming in, then I think you can play lineups with him as the 4.