I used to do the same, buy young 18/19 gens and power train them, but I've changed tact now.

I used to spend the first couple of days of each season going for players who were under 20 and were only one or two cones from being scouts and pushing them on, but then by the start of the next season they were just average 5 (or low 6) players, so I had to either power train them up again or sell to bring new in.

Now I'm on a 3 year cycle with players, letting them see their contracts expire if I can't sell them, then replace them when that happens.

Nothing wrong with the way you are going, its all on what strategy you think is best for your team. I'm setting my team out for the long haul, so want to make sure once I hit the top of the server I am the best team on the game. Thus, at the moment stockpiling tokens and cash is more important than having loads of packs to power train. I'd like to have loads more green and reds (not bothered at all about blues), but at the moment I am ignoring collecting them completely as my quest to grow cash stocks is more important to me.