Are you being deliberately obtuse?
With the usual d20 model, a 5th level character is generally about the same power level as any other 5th level character. But this breaks down very quickly when you have varying degrees of equipment. A 5th level character with a bunch of +3 gear is much more powerful than one without.
With Transformers, you're dealing with the difference between the fusion cannon and a bunch of 2d6 laser pistols. The character levels (which generally define the internal skilsl and powers of someone) are completely overridden by the body and equipment the character currently possesses.
Vance is Right...With a Transformer themed game you will be focusing on equipment more instead of character developement. However to kind of even the playing field you can make Equipment level based, and you can base stats and skills off what "race" they play. Everytime they gain a level their stats go up based off the race they are. Each race specializes in certain area's so they get bonuses to this and minuses to that...or they gain a combat prowess which proves them with a +2 to attack...so on and so forth.
Creativity is hard sometimes to find and muster up. However transformers is awesome for me. I have been watching Transformers since i was old enough to poop. I owned and watched the 85/86 Animated VHS so much that about 7 years ago the VHS Ribbon broke...I was devestated...my childhood flashed before my eyes lol...(sigh) ahh the love for transformers never stops amazing me