Why the bloody hell not? Like I mentioned before "2 classes" kinda like real endurance racing. Lets take a look at the Rolex Sports Car Series. Daytona Prototypes and Grand Touring cars run at the same time, every race. Le Mans does the same thing with more classes. the Grand Am series has Grand Am and Grand Sport on the track at the same time. Its not like this is unprecedented.
Just like in the Kyoto 24 Hour earlier this year there were 5 (if i remember correctly) classes. On the server i was on it was GTR's C-GTR's and GTi's. The GTR's passed GTi's like they were standing still, but in most cases we still had plenty of time to avoid them. Shame that some of the GTR class drivers showed so little respect to the GTi Drivers. They worked just as hard to get there as everyone else.