Last year was my first year playing as well, don't act like I have some huge "experience advantage over you, we started at the same time.
As for Primo, he's had 12 league games so far this season where he's played 44 or more minutes. That means 66% of the season so far, he's played nearly the entire game. Now if you look at the 6 games that he's played less than that, he's averaging 26 points in 34 minutes. That means all of his damage is done in 34 minutes, and the extra 10-14 minutes results in an extra 2 points. Don't tell me that your team has "stamina" because clearly he's standing around racking up garbage time. Also, in 42 minutes he's averaging 11 rebounds, and I have two players averaging that in 30-33 minutes each (as well as 2 backups that get 11 every time they play 25+ minutes), so he doesn't have a huge edge there, either.
Also, just so you're aware, you have 3 very good players... Bartoli will be around for a while and is very solid, so good for you. Primo is 29, and your PG is 30. Players skills decrease at 32. What's your plan, Crunch Time in all of your games to win a title and promote, do mediocre for a season or two and then lose your best players, and then have a ton of 5k salary players on your bench to play while you get demoted back to div. IV? Spend all of your money on brand new players to run until they burn out, just like you're doing now?
Man, I love having a "rival" team.