In most of the stuff I've commissioned, I've tried to leave obvious leap-on points for other people to commission stuff that they like and I am not interested in pursuing; Alpha Fang being especially one of these in that I've tried to ensure there is at least a display of the potential plots regarding both Alexandra and Amy. However, once that option is presented, my further commissions are almost universally spent on expanding stories for an alpha PC (Angie is the obvious exception to the rule here) .
There is some content laid out for future commissions between Carl and Amy and I have some ideas for interactions between Carl, Fang and Alexandra.
I don't particularly imagine Amy as being dominant, while she may become more confident in a higher role I imagine her as both cooperative and conciliatory. I am considering scenes with her standing up for herself and still offering a hand in compromise.
Beyond the initial choice of dominant or submissive, there is no mechanic for switching the NPCs. I agree that one would be nice but I can imagine that would cause lots and lots of variable issues. However, I can see a scene named 'Too many alphas' in which everyone is dominant and the a confrontation erupts, with the PC having to influence one or more library members being knocked off a dominant role and into a submissive role. I also think having a weighting system where some NPCs, if left to long without the PC choosing, will shake out the pack order themselves, with ensuing scenes to inform the PC when they return.