There are about five or six other _small xml files, including UnitPanel. These are used whenever the "small" interface is selected, either by ticking the option, or if the game considers that it's appropriate given the screen resolution. 1920x1080 uses the small interface and I believe anything bigger than that use the "standard" files.
I don't know if ticking the option has any other effect on the interface. I only play at 1920x1080.
The reason for my suggestion is so that people with larger resolutions don't need to select the small interface when they use this mod. Also, people won't suffer a messed up city view if they forget or miss that part of the instructions. The impact of the mod will be limited solely to the city view. I also noticed the small interface warning was propagated to recent mod packs that include the mod.
I don't actually use the mod myself as I have invested a lot of blood, sweat and tears into configuring the city view to my own preferences before I even started on VP (mainly when I had to play on very low resolutions), but I do think it's a big improvement (as advertised!) on the standard view and has several features I'm tempted to steal. My only other user, my brother, has a bigger screen and duplicating the small files as standard files is the workaround I use so that he can use my version.