I use nordgens only for GK, defenders and offensive minded players (AM and ST) just because they need one or 1-2 strong skills and that makes great difference. I'm now on league level 14, still using my GK which is now Q81 (4*) 24 years old, bought him few season ago when he was Q64 (5*). His defensive skill is 94 which is now scout level skill.
On the other profile i'm using strong 3* ST because his attacking skill is on 5* level and physical on 4* level. He is now in 1st team, but if i buy 5* ST with much stronger att and phy skills, he will become substitute.