In this conversation "RF Domain" refers to your expectations for overlapping coverage.
If you need to have one radio environment (RF Domain) with all of your APs in overlapping cells, then you have a bit of a problem.
If you can make seperate areas, for instance one where the AP92 operate, another where the AP103 operate and a third where the AP303 operate you'll have the most work to do managing them, but the easiest time managing the coverage and client experience.
Knowing nothing of your actual deployment or radio environment (so my advice will almost certainly be flawed) here's what I would do:
Manage all three AP families separately in patches - all of each type near one another on one area and the next type in the next area etc. Then start replacing the oldest APs with the same model as the newest until that oldest model is gone.
The adjacent but separate clusters will mean that clients will have to roam oddly, but the clients I have experisnce with seem to handle it well enough in my environment.
The only reason I would suggest this is on the assumption that you'll get budget to replace older hardware - otherwise you're just going to have too many clusters to manage over time.