Should I train him second position?

[Kosowar]

He is already 150 all. So I was thinking only from point of view that new white skills would allow to speed up training with new training rules. But on the other hand I would spend green boxes to open new position and it might make it worthless.

[Ludo_Mansio]

He is already 150 all. So I was thinking only from point of view that new white skills would allow to speed up training with new training rules. But on the other hand I would spend green boxes to open new position and it might make it worthless.

There is no difference between the skills of an AML and AMR, so it won't open up any new white skills (not that you can without going through AMC or ST first, as noted above). Similarly, there might be one or two skills added if you add ST or AMC, but it would make almost no difference to how quickly he gained new skills.

As others have said, if you want to add a position to give you some flexibility during matches then wait until next season when he'll have gone down 20% but will still be young enough to train quickly.

As a slight aside, I'm increasingly coming round to the view that some others in this forum have that special abilities (all of them) are pointless, so think carefully before spending valuable greens on those.