Lag Wagon.
The answer to the question you didn't ask ...
Is cubes .....
End of the day, engines aside, more cubes will always win, when "everything is equal"
More low down, more top end, more everything.
The only reason we have these Rb20 v rb25 debates is that everything is not equal and we have to deal with how engines are built. Rather than having every engine well engineered.
The only draw back that cubes has when technology is equal, is the basic weight of the engine itself. This will affect size of car and weight placement. Probably most important in a track/circuit/rally cars where handling is as important than power. Drags , very little difference, extra power will overcome.