Oh, I see, sounds interesting.
I assume starcraft has completely assymetrical factions by that definition too?
Eh.... Starcraft is somewhat asymmetrical for sure, but IMO that is largely cosmetical. Each faction has the same unit roles available at pretty much the same tiers.
Late game units are very asymmetrical and base building is quite asymmetrical as well.
No doubt it is one of the most asymmetrical RTS games, anyway. Along with Universe At War and Grey Goo (yes, both are not exactly great, but that's not the point).
Warlords Battlecry 3 is also rather asymmetrical when it comes to units (Grey Goo is the other way around).
I don't think there has been a truly asymmetrical RTS, yet. Mostly because "muh balancing!" MP shenanigans. As if making all factions of the same strength would be the only way to get a good MP going, but I digress...
Though I did not play this one - ratings deter me so far.