They are I believe, (the two) different wheel bases.
That is also why they whited out some sections.
I 'guess' the point is, the differences you are talking about as possible and negative ones at that, do not add up to much within this specific vehicle program - when you look at what they are actually offering and most importantly, how they are actually built.
You seem to be assuming some things, including that the intent here is to offer FWD, RWD, and AWD fully interchangeably - up and down the entire product line.
As MB makes quite clear - that's not the goal - nor should it be.
That is also somewhat obvious given the the various / available dimensioning, payload / gvw groups and for all the roses, the PTs offered.
Plus..... MB's presentation text and press materials.
I don't have a position with all this - seems like a clever or clever enough vehicle program that will allow them to cover a lot of ground 'with less' compared to some others efforts - who would perhaps require a more diversified, complex and costly effort - up to and including two separate vehicle programs rather than say one and a quarter.
You also keep postulating other things that MB also addressed both in terms of the vehicle itself and the information released as of yesterday.
Like a lot of theorizing while ignoring the actual product and information provided so far.
As an example,
According to MB's written press release for this introduction, floor height - is the same on all variants or all cargo / commercial variants if that's wrong.
If anything, they all appear too low but that's a matter of preference and so forth.
Nothing personal, but you also seem to be over estimating the vertical changes as well as their impacts - as well as their locations relative to the front seats and so forth.
Pretty much along the lines of what you did with regard to Audi and the Intrepid.
Now take a good look at that RWD driveshaft . Notice one, the 'direct' attachment to the AT, two, the dirt simple u - joint and simpler yet flex joint - going to the relatively puny third member - and that this is all they need to use.
Nope, none of all that is bouncing around much in the vertical is it.
Just because some others might be challenged more severely to accomplish all this is no reason to tar and feather this one.
You know, in so so many ways that matter....... this is not an E350 versus or crossed with a Transit.
If MB wants to segment things a little differently than some other OEMs - whose to say that's wrong - or a lousy approach ????????
I was going to let this one slide until we have much more detailed info - because of the effects of wheel bases ( 2) oal lengths and heights ( 3 x ? ), wheels, tires - etc etc etc ( big varied program ) but even from the little out there, it does not appear to be anything but fully useful in all PT builds - your criticisms and assumptions going in as well as out appear to be unfounded.
A little bump underneath the center third seat in the 'cab' ..... is no big thing. And that's not a given just yet - haven't seen it in the pics so far.
All - as built come under under the 2 Metre height limit.