Does Fire-rate Decide a Fight?

This is meant as a serious discussion on the topic of fire-rate disparity between weapons. I am in no way advocating for or against any playstyle, weapon choice, or meta. I simply wish to see other's thoughts on the topic. With that disclaimer made, I present a hypothetical:

Assume you come across another player on the hills of customs. You are at what could be described as 'short to mid-range'. You're both equally skilled, geared, and aware of the other. You have access to equal cover, have similar knowledge of the area, and reposition equally well in a fight. The only difference between you is your weapon. One of you has a fairly-well-modded AK74 with BS rounds; the other a meta MPX with 7n39 loaded. Would you expect either to hold an advantage over the other?

Obviously a situation like this is heavily controlled. We have established variables in such a way that the likelihood of a fight beginning in this way is near impossible, if only very unlikely. And yet, I would hazard to say that many of you have already answered the question in your own heads. If you abstain under the pretense of 'the outcome being still too variable' I will concede to that point. However, if you can look past the scenario and truly ask yourself 'who would win?', what would be your answer? Do you have experience or a pre-conceived bias that lead you to that conclusion? Bonus if hard evidence is presented. If so, please share!

To make it fair, I will answer with my own answer and the thought process behind it. In such a situation, I would wager that the MPX user would win in almost all encounters. This is based completely on anecdotal evidence as an AK user who has recently been monkeying with SMGs and other high-fire rate weapons. With slower weapons (AK obviously included) I find that a moving target is very often able to sort of step 'in-between' my shots, as it were. The lower fire-rate gives enough frame-time for a bullet to sort of skip over the target, whereas a high fire rate is more likely to make some sort of contact. I think of it as the difference between attempting to jab a line of dots down on paper with a pen as opposed to simply 'painting' the line down with a brush.