In which case one league can simply entirely leave their current league, and all join the other league.
Why write a program for this?
Creating work for no reason.......
Similar functionality in another fantasy league I play. Coding required for any change, but its a function that would allow league to seemlessly switch.
"seamlessly switch"
yeh apart from if...
1) The sum of the players from each tier of both leagues, meaning more than 32 cars a tier
2) the moving players don't like the format of the new league, they'll have to leave
3) Someone inadvertently loses control of the league
4) both leagues are currently at different gp
5) any races have been completed, what happens to the current points of the players? Taking away someone's championship would be super harsh
If all these are ever somehow fixed then how similar will one league have to be to another to be able to merge?
There's no point, just have the league host message players and tell them to join the other league; if they don't want to join, they won't join. simple.