Hi again Shmantz,
I think you'll actually be getting outside of UL and into the NEC for the main disconnect sizing.
Your five motor loads can be handled as multi-motor equipment -- the feeder will have to be sized based on nameplate FLA, not measured FLA. Basically, the feeder has to be able to handle all the loads that can run at once, plus an allowance for the starting current of the largest one (125%). Once the feeder is sized, its overcurrent and short circuit protection can be chosen.
I don't have my NEC handy -- but it would be worth your while to look at section 430 under multi-motor equipment.
To satisfy UL, you just have to make your feeder protection 125% of calculated, with an upper limit of 80% of the feeder ampacity.
That may all sound confusing -- but that's because it's a bit of complex calculation to do.
Let's see if anyone else responds to simplify it. You might consider flagging this post for deletion, and re-posting your question in Electric Motors, Generators, and Controls Engineering forum. Some really good minds in there who have dealt with this before.
Good on ya,
Goober Dave