I don't think that any developer or Nordeus Manager will give you a clear answer on this question. Some say that it's important to place right foots to right, left foots to left, while others say it's not important.

Personally I think it's not important, my players are playing awesome, my left foot AMR is scoring many goals and he passes often. If you can't decide, just buy players which are able to shoot with both foots.