Two pieces allows you to slip the spacer in.
There is a lot to move, yep. It isn't a simple Sunday afternoon project at all yet seemingly looks like a very simple, innocent procedure. The "Devil is in the details". Exactly how you accomplish that is up to you.
From a design perspective it appears that the location of the foot pedal plate was somewhat of an optional detail. Stock, it appears to me, that it was put at the shortest distance possible and I'm wondering how that location was finalized since it seems obviously located for small people?
It does seem to be consistent though with other cabin positioning details as if almost a spite thing against Ford's involvement?