Can GTSeries and Endurance Series be replaced with 4 Single Seater Racing Series when modding?

[GoofyWillows]

I am working on a mod at the moment where I would wanna have at least 4 Single-Seater Series (F1, GP2, Formula 3 And Formula Renault 3.5) and maybe 1 GT Series and 2 Endurance series if the game requires 7 racing series in order to work properly. this would mean that i would remove GT Challenger series out of the mod in order to push in Formula Renault 3.5 series in the mod as a way for the long list of young drivers that were around at the time of the mod to be able to have seats in Single Seater series instead of being stuck as Test Drivers or be unemployed. does the game require both GTSeries and Endurance Series in order to work correctly or can one of the GT or Endurance series be removed and replaced by 1 extra Single Seater Series?. If the game doesn't support 4th tier could Formula Renault be added as a 2nd tier for Main GT series with Promotion turned off and 2nd tier of GT Series really being the 4th tier of Single Seater Series? (i don't have Promotion on for GP2 and F3) this may be a dumb question but I have never modded a game like Motorsport Manager and wouldn't wanna edit a game for hours just to find out that things that I changed mess the game up.