Debian Multimedia :: How Come Same Font Smaller In Xfce Than Xubuntu

When trying to make my Xfce desktop in Debian 7 (wheezy) look the same way as in Xubuntu 12.04 (precise), I am able to (by copying some files from Xubuntu packages) make the fonts render the same way, set up the same desktop and icon themes etc and make everything look identical, with the exception of the fonts...

Since that, if I choose the font "Sans 10" for my desktop, in Debian - with all the same anti-aliasing options, and such, that I use in Xubuntu - the text looks smaller, everywhere, compared to Xubuntu.

So... How come this happens, if I have chosen the same font "Sans" with the same size "10"?

Below, are the different results, depending on the OS in question.

In Debian Xfce, I get this:

While, in Xubuntu, I get this:

I remember this same thing happening, once, when I was experimenting with setting up an Openbox desktop environment, on top of an Ubuntu 12.04 command line install, where, if I used LightDM, as the login manager, I would observe this same font size "reduction" (in, at least, some of the applications), with the theme I was trying to set up, while, if I used GDM, as the login manager, I would not observe this same font size reduction. (And, so, it seemed that some GTK library(?), being used by the GDM, prevented this from happening(?)...)

Also, I read somewhere, on the Internet, that Xubuntu builds Xfce on top of GNOME(?) (libraries, I guess)...

Could it be that, by installing some GTK library, the fonts will "return" to normal size? Or, do I have to configure something else, somewhere?

(P.S. - I've also tried choosing the size "11", in Debian Xfce - in case it's a matter of different values used, for the numbers, in each OS - but, if I do so, it only makes the text bigger than in Xubuntu, with the size "10"...)