One attribute badly missing is routine. In real life, Senior players can compensate a lot and here it is almost better to run a youngster team because you can develop them for the upcomung next levels. If you want to play for the championships you have to get rid of players latest age about 25. And this is not true to life.
A propsal can be the more minutes of play the more routine > this forces you to field them when they are young (= with less routine) so you have to consider it well