My concern is Brightline is going to need even more train sets and passenger cars. The train sets for Tampa and more especially if JAX ever starts. Right now, based on deliveries of Siemens equipment it would take several years delay in getting that equipment based on the present orders Siemens has. When construction of the building is complete the Siemens NC factory may concentrate on the Airo deliveries first.
How quickly the NC factory can get, and train enough skilled workers will also be a time of passenger equipment construction metric.
So, from what I recall working up a few years back, Tampa needs about another 5 sets: Tampa is about 90 miles from MCO, so you'd need 3-4 sets to make service work (4 seems like the better number to work with), and then I presumed an extra spare/protect set. This depends a bit on whether Brightline runs trains through (MIA-MCO-TPA) or forces a change at MCO. I suspect they would run most trains through. The wrinkle is that when you look at the old HSR plans, it was expected that you'd essentially run one set of trains MCO-TPA and the other set Disney-MIA, using the overlap to deal with the flood of probable demand in the Orlando area.
JAX is trickier to calculate - I'd use a placeholder of a six-hour runtime to Miami (it could conceivably end up a bit closer to five hours depending on various questions about speed, etc., but six hours seems like a safe bet) and three hours to MCO. I'd suggest that Brightline has three options of what to do here - they could send all of those trains to Miami (this would require about a dozen sets), all of the trains to Orlando (6-7 sets, and add a few if you want to run through to Tampa), or split service (probably around 10 sets, depending on the mix). I believe that my original calculations came out to about 25 sets, but it assumed:
-Hourly Miami-Orlando-Tampa (15 sets)
-Every-other-hour Miami-Jacksonville (6 sets)
-Supplemental trains in South Florida for twice-hourly service south of West Palm (2-3 sets)
-One additional miscellaneous shop/spare set (partly due to scaling, partly due to all the grade crossing incidents).
Re-working that for hourly JAX-MCO service would yield about the same train count (though you'd need to add 2-3 more sets in South Florida to get to twice-hourly down there), and doing split-service would probably require about four sets JAX-MCO and six sets JAX-MIA (so about 27 sets, presuming you don't go to Tampa with the Jacksonville sets).