The numbers are just marketing names. They're meaningless as far as making comparisons or determining if a motor is suitable for a particular application. Ford calls their truck an F150, but Chevy calls theirs a Silverado 1500. Same thing with the motors... 400, 480, 22/33/12... It's just arbitrary, so don't let it confuse you.

Comparing motors isn't easy or simple. In fact, comparing motors to figure out which is "more powerful" is really a lost cause because you can literally MAKE any motor more powerful than another by adjusting battery voltage and/or prop size. Find motors that will do the job, then compare using other means, like quality, price, support, etc..