This is what I did in the first season of utopia and I still have the 2 better guys I trained back then. Yes training 5 guys instead of 2 at lower potential might ease the cost issue.
the fan survey and merchandise benefits that accrue?
If they are not from your nation you get a boost of 1 ball or so in the fa survey in my experience and with a basic PR manager I was still constantly below the league average in merchandising even after 2 seasons with mostly the same trainees.
I don't know how to value that on the ledger, but I do know not having to go out and buy a backup guard/SG/SF every few seasons and eat depreciation there is worth it.
I don't believe depreciation is a significant factor between 25 and 30. I might agree it shouldn't be like that, but unless you overpay I think it's a fair assumption to think you can resell at a minimum loss, if any.
Yeah, I wouldn't ever suggest training just two guys with lower potential with anything more than a basic trainer. The benefit of higher trainer levels is finishing players faster or training them closer to their maximum, and when you've got a lower potential ceiling to reach, it makes much more sense to either spread training out to more players or use a lower level trainer (or both).
Two seasons of trainees isn't going to put a noticeable dent in merchandising, I agree - that's more of a long term thing. I've always been well above average in merchandising but I've pretty much been all-American for a long time now, and six of the nine players in my primary rotation joined the team at age 18 and are all are at least in their twelfth season on the team.