The reason SS Goku would loose to SS2 Goku is that SS2 is a superior transformation compared to SS.
The last known power level that is ever measured in Dragonball is Future Trunks, at 5. After that, people who relied on power levels stopped showing up. Mostly because they were all dead. Because of that, we can't definitively know Cell's power level, or anyone past the Androids for that matter. So the numbers Electric Boogaloo gave for Cell and Broly mean nothing.