<now I feel accused, hopefully there's no witch hunter among the readers> 
I don't want to bend rules.
I do NOT try to justify, for my sole benefit, an extreme use of a hard to believe combo.
My aim was to allow all willing people to use a legal combo, that they might not have thought about.
The way I have read the rules is as follows:
I saw a sentence starting with the word "If".
Maybe I've spent too long a time in computer science, but when I see an English sentence starting with "If", I expect the structure to be as such:
If {condition} then {consequence}.
Such sentence usually implies that {condition} can be met, or not met.
Naturally, I came to expect that there could be a case when {condition} was not met.
I only found out in this thread that many of you guys consider that {condition} is always met, so that's not a condition.
You guys react just as if the rule was written with the word "As", or "Since".
Apologises if I reacted as if the rule started with "If"... hey wait, it does start with "If"...
"Eppure si muove" (Galileo)Hopefully, Your Honour, you understand now better how I came to the conclusions shown before.
Calisson, if there are two possibilities in paragraph "When footprints collide" why only one of it is described?
Because only that one introduces a divergence from the normal rules, perhaps?
The full conditional sentence is normally: If {condition} then {consequence} else {other consequence}. However, "else..." is not mandatory.
When {other consequence} is not mentioned, that means that there's no change from normal situation if {condition} is not met, period.
With the above thinking, any model can fit in the back row of a DemiGryph unit that does not have a back row; heros on dragons, etc.
Yes.
Why not? Is it any more strange than placing a Pegasus inside infantry?
BTW, thank you for making the effort to understand how I came to diverging conclusions - that I require nobody to share.

Overall, I'm rather sorry that such rule discussion took over such a large space. It has been polite and argumented, thank you all for that.

Still, as we are here, could you tell me how you would place a WP in or next to a unit of 2+1 DG, FC?
Would it result in the WP being in front aside two of the CG, while the 3rd CG is left on the 2nd rank?
That would be odd, wouldn't it?
Or are you telling me that it is the case (4) of BRB p.98, when no solution is found?