@seanmeg
You ‘re right my friend but there is a misunderstanding. I was talking about a team with many fast trainers, not to pump up 1-2 players to 8* or 9* .
My strategy is to have many fast trainers, starting with 5* in the beginning of the season and getting 6* later. A 5-6* full team has enough quality to go after the double (with proper formations ofc) . The Cup it’s another story.
I have sources but they are limited so I don’t like to power train 7*-8* players and getting +20 , + 30 and worried about injuries.

This is my team for example. All the 5* players are Q49 and some of the 6* are Q54.

Click image for larger version.  Name: 12-3 pt1 - pt2.jpg  Views: 28  Size: 96.7 KB  ID: 33699

Today I had 2 trainings, 3bars/practice and another 1 I ‘ll set later and maybe a second for the players who ‘ll not participate in my match.
So, returning to the subject of the thread, when I see my rival opponents when a league or a Champions League is starting, I ‘m not only checking the qualities but the age of the players, so to guess how those teams will develop during the season.