Exactly. Throttle controll is much easier the higher the gear selection goes with vehicle speed. You can run %70 throttle pos in 3rd and hook, but 70% in 1st no way. The margin of error is MUCH higher the LOWER the gear ratio is. if you graph it the ramp up from hooking first gear would be like +/- say 60% throttle input and hooking 3rd gear is like +/- %15 throttle input.
Now take the time your in each gear. 1st lasts about 1 second, and 2rd lasts about 5 or so lets say. That MULTIPLYS the odds of hooking greatly with the given examples above.