I totally agree with the big picture, so not attempting to disagree broadly. And you seem to be entirely correct about how this idea was interpreted, or implemented, in the game.
There are also, no question, more variables going on when saying who would land shots first when inside the pocket. Unfortunately, I don't think much goes into gameplay right now.
But, for the sake idea sharing (and hopefully someone important reading), other considerations are things like the straightness of the punch, combined with the amount and type of torque in the technique (beginning with footwork, then leg/hip load, and finally the general length of windup). It's probably also worth noting, if all else were equal, the shorter armed fighter would also, potentially, be able to land at the end of his punches.
Just for real world evidence, recall Riddick Bowe (depending on age in here), and you might remember a big heavyweight with one of the best, and most underrated, inside games in heavyweight history. (For those not old enough to remember, go back and watch his fights with Evander Holyfield, which had a lot of great inside work from to completely different body sizes.)