If you ride short tight tracks you are probably better with the shorter gear ratios. However, 4 strokes allow you to be in the neighborhood of correct without punishing you like 2 strokes do. It will also depend on how fast you are not to mention, how early and how quickly you pick up the throttle coming out of turns.
Longer gearing will sometimes force you to become faster through turns so you don't lose momentum and drive. Steep learning curve though. lol
These guy probably have you pretty close. Play around and see what you get.
Good Luck!!