I'm only on lvl 3 and bought my first Nordgen player 2 days ago. I had one already (and still have him playing) from season 1.

19 years
high lvl 4* (only 2 skillpoints from 5*)
Striker
Bought from: AC Muddy
Training: 200+ for a full workout. HML= 37-78-100 (roughly)

I do notice that these players perform usually above their lvl. They can hold their own vs better players in my team, even outperforms most,
So, 2 skillpoints for a full training.