i would do the best for his progress, and that have nothing to do with german diviison that are just my experience with starting rooster.
And the best thing is to get a good rooster fast and for this he need money and quality and such thing he doesn't gain with stamina training for two players, with two "good" player it makes more sense to train then specific ...(else they would be overpowered, but in my eyes they but i would go that they are a bit weaker then two position training, and i would say this in cases with a normal sized rooster with quality in it)
In my eyes ft and stamina are pretty weak training for single players who just getting attractive through the point that they train much players and are indepent from the minute, but i would always try to get skilltraining before you get a bit quality in the mass from your players.