In my very limited experience plum and apricot get along, but I don’t know for how long. As for Nanking cherry it’s not really a cherry - much closer to being a plum, and plum grafts to Nanking cherry (prunus tomentosa) very well. It dwarfs the plum a lot, also almost completely stops the root suckering this prune plum of mine is famous for.
I chipped an apricot bud to my prune plum (on its own roots) last year and it took off; how long it survives I can’t tell yet, but I’m optimistic. Apparently, apricots are furry plums? And I think I have enough growth on one Nanking cherry seedling to accept a bud, we’ll see how that works.