I thought about this for a moment, and am wondering if I misunderstood something.
The going theory is that, when a man in the company's front rank falls, his filemate in the rear rank steps forward to fill the place in the front rank.
If both files fall, both company ranks dress to the same flank (right or left, dependent on orders, usually based on placement of battalion's colors).
Where I may have misunderstood things is the actions of the rear rank after step-ups have occurred. I was assuming that, after rear FILE step-ups (I was saying rear RANK step-ups in my previous post which, while not wrong, might cause a little confusion, so I'll try to say FILES when referring to step-ups now), the rear rank would dress. I, thus, was envisioning a short rear rank as opposed to the front rank and, especially in the case of dressing to the right, there would eventually occur situations where the front files would be significantly taller than rear files, which would lead to somewhat dangerous firing conditions if the front rank remained standing.
I'm wondering now if, after rear file step-ups, that the rear rank would dress beyond each rear file moving to remain behind his front file. In such a case, while prone to confusion as the lead flies, the height differentials between front and rear files would remain the same, and favorable conditions for firing.
Am I understanding things better now, with this new thought?