Haha I was agreeing with everyone saying digimon are overpowered, but then that last comment about mega stones threw me.
With so few megas existing right now, it would be easy to create more megas that have comparable power.
I think in large part, it would have to be about looks a lot.
Lets consider Augumon vs Charmander.
This honestly seems like a pretty balanced battle.
Greymon vs Charmeleon, well thats a bit off since greymon is quite large in comparison. As far as their actual pwer though, it might be hard to say one is actually more powerful than the other. Certainly one looks more powerful due to size, but meh, remember piximon....
Charizard vs metalgreymon
Again, digimon looks more powerful due to massive size, and now loads of armor. Metalgreymon literally shoots giant missile things.
Mega charizard, especially mega charizard x (because of its coloring) actually does look like a potential match for the scaled down final digivolution, wargreymon.
Comparisons however result in a lot of other seemingly poor matches - blastoise vs joes ultimate giant turtle thing, hammer would serve up blastoise easily.
Then again, Venasaur vs that little flower cannon girl, meh, venasaur could probably blast that thing out of the sky.
So who knows