Some years ago I was a QFI on the C130J when they cut 15 hours out of the MELIN cse at Cranwell. A brilliant wheeze from some staff officer to ‘save’ money in training which no doubt boosted their promotion prospects. So we received student co-pilots with even less experience who if they needed any flex (which many did) to make up the deficiency then blew the ‘savings’ - £3000 for a flex sortie in the simulator, circa £15000 per hour in the aircraft.
If they’re going from a T6 straight to an operational ME type then the cost of any additional training would blow any savings out of the water. Although the modern ME types aren’t as demanding to fly engines-out as those of old you still need to learn on a small, cheaper aircraft rather than an A330 or A400.
My father-in-law went from the Vampire T33 at the end of his training in 1960 straight to the Shackleton without doing ME training on the Varsity, he described the experience as ‘quite tricky…!’
As to having a non-aerobatic aircraft for AEF, it would take away a key part of what the kids love and you might have fewer volunteers to be pilots too. As for a 4-seater, almost all of my cadets love doing the flying themselves and it helps distract them from feeling airsick. With 2 pax in the back seats you’d be almost guaranteed to have at least one throw up on every flight so you’d never get anything done.