Assman input - can anybody explain please?

As mentioned in another thread, I've been experimenting with 3-5-2 and 3-4-3 formations to try to get something workable going. Something strange appears to happen with the assman input with these formations. I get the comment 'Our midfield is being outnumbered (3-5-2) or heavily outnumbered (3-4-3) by X's midfielders' cropping up from time to time when the opponent is (for example) playing a 4-4-2.

Now I know my maths is bad, but I find it very hard to understand how 5 midfielders can be outnumbered by 4 or even how 4 midfielders can be heavily outnumbered by 4!

Zico noticed when he was experimenting that if he lowered the mentality stats of his wide midfielders in a 3-5-2 this comment appeared and that raising it made it disappear again.

The odd thing is that if you replace wide midfielders by wingbacks your assman promptly shuts up about this (even though you now really ARE outnumbered by 4 to 3). He also stops saying it if you replace the MR and ML by AMR and AML.

You can win matches and play quite decently in spite of this 'outnumbering' thing, though. Can anybody explain what's happening, please and how this assman advice should be interpreted?

I think it's more to do with possession than actual player numbers.

I could be wrong.