[Kuppi]

Sim through the first 25 years of any fictional league, erase the history, release all players and do another inaugural draft. The players the game creates for the inaugural draft are...weird, and different from those generated through drafts and scouting. I've found that this player pool tends to include multiple players with pretty insane stats that you would not see in year 50 of your league (or if you do, it'll be one guy, not five). This makes leagues top-heavy.
What kind of league totals are you getting with 2015 settings? If the overall league production is fine, then it is mostly an issue of these inaugual players being OP.

Check the park factors, too. I had a league once where the game created a stadium that had a 1.230 AVG modifier for lefties.

Or just manually edit the league modifiers. Lower the hits modifier by a few points, see what happens. Edit the modifiers, not the totals.

This will never be perfect though, don't even bother. The game tends to distribute the league totals more top-heavy than in real life, that's just how it is. I tend to shoot for a league with about 5000 HRs, yet the top power hitters will routinely hit 50+. If you use the 2019 stats...oh boy.