No, what happened was all your skills for the players would have been near popping. So any regime would have had a similar effect. The regime you switched too probably just matched the experience distribution. So coincidence.
Regimes don't get less effective in the amount of experience they give, what happens is players that are older or better take longer to pop. So there is a gradual slow down as the season goes on as your players age and get better but it's nothing to do with the regime you select.
Founded season 15 matchday 4, 22/10/2013(15th of March 2027)
Iron 3 Champions 2028
Steel 1 Promotion 2031
Bronze 1 Champions 2034
Silver Runners Up 2035
Gold runners Up 2037
Gold Promotion 2041
Total Competitive Record: 723-544. 57.06% Win