The 346 is a fantastic aircraft but, in my opinion, is too far beyond what you need of a training platform and more akin to a frontline fighter. The jump from Basic Trainer to jet trainer would be a little too big.
Bob, that's something I wrote a paper on once! You have to have a jump at some point; either the leap from T2 to Typhoon/JCA, or the jump between Tucano to M346 or equivalents.
We used to effectively have a 4-tier system before OCU; Tutor, Tucano, Hawk T1, Hawk T1A. There'd be room for a realignment back to that, with a smaller jet (like the M311?) filling the traditional FJ AFT role before something more capable like the M346 does the TW stuff.
Alternatively, you make your basic trainer more competent. They're already trying to introduce some of the FJ AFT syllabus into BFJT, and if they were operating the M311 or even just a heavily upgraded Tucano they could do a lot more to bridge the gap. Some basic trainers even had this as a selling point, that you could put it in a "baby" mode to restrict power and access to more complex systems, unlocking things like the simulated radar and full power as the student became more capable.
Something like the M346 would have enabled us to look at the companion trainer option too. Fit a Typhoon cockpit to it with an appropriate datalink, and then your poor Typhoon mates getting 10hrs a month have a fleet of cheaper aircraft to help maintain basic skills, play as the bandit, etc etc. A bit like some USAF units do with a horde of T38s next to an F22 squadron, fly them when there aren't F22 hours available and you also have free DACT on tap. I think EADS were looking at selling the Mako (is it still going) as this sort of aircraft?
That's what I would have done. Extend EFT a bit to introduce more concepts, and up-rate the Tucano or replace with the M311 for an old-school 2-part BFJT, with the latter part incorporating most of what 208(R) used to do. Something very capable like the M346 for TW, and as it's an expensive aircraft doing a short course, let it drip over into a companion trainer role with some of the fleet at the FJ MOBs, or paired with the OCUs to reduce some of their training burden.
The current system means we don't need more from 22 Gp, and we don't need a twin-engined afterburning advanced trainer, but it does mean there's a lot of work uploaded to the OCUs that could be done earlier and for less.
Not to say the T2's a bad choice per se. I haven't flown it, but I'm led to believe it at least now lets you teach AMRAAM tactics and simulated radar handling?