Completely pointless.
If you want to "pit" two engines against each other then you need to run them when they are not in dumbed down mode to play against humans. I.e. at their highest level in a game with equal built in time controls on both sides.
As it is you are just testing which of the dumbed down settings you selected for each engine happen to be more dumbed down (and it should be obvious that the "ratings" for the dumbed down modes are just estimates).
I just pitted these two engines versus one another via using the the 1605 rated character from Chessmaster and the Chess.com's 1600 setting. I made Chessmaster play with black since it has a stronger rating, as far as I can tell. Who do you think won?