Hi also agree with your idea. It has always been discussed that training is hard and people usually complain, asking for a much easier solution.
I think training should be hard, but not that hard. If you want to train a NT player with secondaries, you really need to sacrifice your whole team to make it happen. Since most experienced players are from top leagues, they like to remain competitive and avoid training. I think every tier of team should be able to train NT caliber players from scracth.
I don't know exactly what the solution might be, but I also dislike those really simple plans where you just have to choose what to train, and bam...its done. I think it should be thought but not this hard.