Transfer funds between 7's and 15's.

I've been playing both 7's and 15's for a long time and spent quite a few £££ on players, coins etc. If Sweet Nitro is getting the money regardless, why can't I transfer money I have built up in 15's to my 7's team and vice versa???
not a visa player like but surely you chose what game you spend your money on ? What i'm getting at is why would you want to transfer money if your able to choose what game you spend it on ? To i don't mind the transfer of money your money you spend how you want where I personally disagree is if that was to come is players like yourself would basically be rewarded for simply having more time to play multiple SN games which isn't fair to people who can only play one or the other and would not agree with the potential ability to transfer over players for me thats too far You could be a level 120 on 7' s but feeding an account thats 115 on 15's