Alright, I think that works.

I figure though, their air bending gene is replicated but they would agree that since numbers are so few, they want to pick those carefully. I do think by our second skip though, there should be at least one air bender popping up. I also think they could start (Xano and Xana) with wanting to give good people bending powers by taking it away from jerks or those unworthy. I think the turning point we could use would be Xano (the guy right?) taking money for bending talents. While Asami gets water bending (probably soon after the second skip) I think Xana would be unsure about giving her more than two since we could say Xano was the one who wanted to create his own Avatar while Xana was more into the science and tests, rather than using them for selfish reasons. By the time Asami is given earth, I assume Xana would then give Asami the elixir to give to Tenzin and Lin since Xana thinks they could help combat her brother and soon Asami?