I dont think a drift edition is necesary. In LFS you have a lot of cars with realistic simulation, so you can race, drift, drag, rally or do what you want.
The number of licenses doesn´t matter. LFS is not a game made for money, it is a game made for LOVE, love to racing, love to cars, love to tracks. Perhaps this is the reason that LFS is the better, because is not made for money, it is made by the heart, made bay people that doesn´t want money, made by people who loves racing.