Guys, do you know if a "3 star" fast trainer has less potential than a 99% FT?

I have always taken that for granted. But I have realized that at least one 3 star player I picked up kept up pretty well with more developed FTs.

Sometimes it can be hard to find a fast-trainer in the right position etc. And this morning I saw a 59% fast-trainer that had both two positions and a SA I wanted. Its a bit of catching up to do, but instead of taking a kid that has 99% that needs one or even two positions and a SA, the effort to push a kid from about 59% to 99% is basically comparable. But its of course not worth it if the 59% will hit a potential roof much earlier.