I don't have much exp about T youngsters, I 've bought only 1 who was fast trainer and had so far some 0T for a while (for the Cup draw).
The 0T were from slow to medium trainers.
but it's pretty weird that while in all the others newborn players/programs like nordgens, scouts, players from a new/bot team, there is a steady pattern about training, in academy players there is a lottery pick element.