I do not agree in this case but it's ok if we have different opinions. If it is guaranteed that the young players get perfect training and will advance to the NT, it would be be best (imho) to give them as much experience as can be achieved. That doesn't mean that you have to leave out great 21y olds. But if you have a 19y old with 78 TSp and a 21y old with similar skills but maybe 81 TSP, I'd usually decide for the younger guy as he is the future of the u21 and possibly NT. If you have less than 90 TSP when a players turns 21, it's almost impossible to get him into the NT. Might work in Scotland for a couple of seasons yet, but I'm not sure (and hope!) it won't stay like that. So in this case, the Highlander would have my support. But we can discuss further of course and a compromise is almost always possible to be reached.
Du hast nicht genug Geld, um dieses Gebot abzugeben!