They look great. The shading and the rubble-strewn bases are quite effective.
I wouldn't worry too much about the particulars of the shades on the greatcoats. Soviet wartime uniforms often varied considerably in the amount of brown vs. the amount of green, and for greatcoats also the amount of gray. This reflected factory-by-factory and lot-by-lot variation in the quantities and qualities of the dyes available, and also the tendency of uniforms to fade depending on the particular soldier's exposure to the elements (and to laundry facilities).
Of greater concern I think, in regards to the uniforms, is the soldier in the second picture in the telogreika (quilted jacket). The telogreika was new enough to be uncommon during the winter of 1942/43. And those that did make it to the frontovics in the early war had high (folded) collars. The more familiar telogreikas with short collars (as I think the picture shows) did not become common until 1944.
Also I can't quite tell, but it looks like the kneeling soldier with the SMG has a PPSh (proper), but with a 35-round banana clip rather than a 71-round drum. It was only after Sudayev's PPS-42, an SMG with a banana clip used in limited numbers on the Leningrad front, beat Shpagin's PPSh-2 design as the Red Army's new SMG for 1943 production, that a similar 35-round banana clip was put into production for the original PPSh. So PPSh's with a banana clip are really post June 1943 phenoms.
Kind of counting bolts and button I know, but still if you want to get the details right I think the greatcoat shade is the lesser issue.
Take it or leave it at your discretion.
-Mark
(aka: Mk 1)