Just watched the video on Facebook, this is going to be a serious resources sink. Can't be sure but it looks like at least some of the players cost tokens to bring them in to the youth academy in the first place. Then hiring coaches is going to cost tokens and greens. For a 1.2x coaching boost you have to pay 15 tokens and 25 greens for 7 days. That seems like a lot for not much return to me.

The next levels of coach (1.8x and 3.2x I think) are even more tokens and greens.
Click image for larger version. 

Name:	Youth academy.jpg 
Views:	43 
Size:	27.4 KB 
ID:	131053