According to what I have here, the TE of both engines is 35,100 lbs., giving #5 a healthy adhesion factor of 4.56, while #3 (Mt. Emily #1) has a magna-traction-inducing factor of 5.41. Better yet, "little" #4 has on 30,350 lbs of TE, with a working weight of 85 tons. That gives her a stump pulling factor of adhesion of 5.60!

If you put #4's and #5 up against the same heavy train, #4 might pull more than #5 IF it could get it to move. One of the issues with #5 is it was built with rather lightly constructed line shafts and universal joint horns, which it has been known to break in the past when worked too hard.