These guys are 'auld skool' 1980's IG, from the days when they were Imperial Army. Necromundia 9th on the box cover, etc. So they are reinforced by the very occasional Cadian, but more oftern than not, Urban Mammoth's Viridians. The viridians are generally a better match.
They have grey uniforms and purpleyblue helmets. Which caused CNJ to comment that they looked like UN troops.
HQ: Gen Marcus Firth & command squad.
Troops: two platoons - command and four squads.
That's it. They do have a scattering of missile launchers, HB & LC, but these are embedded in the squads - They are supposed to be descended from Skittari regiments, hence the man portable LC and one infantry squad armed with bolters.
And Corporal Hicks, of course.