What is the difference in the one you took out vs the new moog, is it .22", that is almost a 1/4". 54mm = 2.125, so yea 2.125 - 1.900 = .225" so that ball joint should fall through the hole in the control arm.
he wasn't comparing the same application for ball joints, one was thread-in while the other was press-in...
on installing the new balljoints, the threads are already cut from the originals, thread in the new ones until they are as tight as makes you comfortable. if you need peace of mind then do the tack weld thing. done.