If both have IDENTICAL props rotating at identical RPM, there can't possibly be any difference in performance.
So if you took the engine and prop off a Europa and stuck on the front of a Tiger Moth the performance would be the same?
More seriously, I suspect you meant that the engine performance was the same.
Even then you're not right. You could fly a 172 at the same RPM with no flap and with 30 degrees of flap. You would use more fuel and fly more slowly with the flap because the drag had gone up.
Although the engine is turning at the same RPM it is actually producing more power, so its performance is not identical.
Mike