I built a 6mm Romanian force a few years ago.
I initially planned to use Italian figures (not Soviets). Soviet SMGs and LMGs are distinct in appearance and would require significantly more work to make into Romanian kit. Italian SMGs look very similar to Romanian, and the LMGs can be mod'ed just by adding a magazine on top.
Another choice would be French figures. The LMG will match. But the trenchcoats only work if you want winter Romanian troops (summer Romanian uniform used a light "blouse"). And the French helmet is rather distinct and different from the Romanian helmet (which was a Dutch design). But … some of the Romanian troops, particularly border troops and second-echelon forces like AA batteries, actually used French helmets which had been supplied before the new helmet was chosen.
All of that said … in the end I went with GHQ Romanian figures. They are really nice figs! But alas, the helmets seem just a bit over-sized. Still, it worked well enough, and I am pleased with the results.
I did resort to Soviet figures for gun crews, as I could not find any other solution.
Some pics of figures and vehicles …
An infantry company, all ready to go.
A closer look at some of the figures. Rifle squads get 4 figs -- 2 riflemen and an LMG team. This pic also includes 3 man (special purpose squads) stands for the platoon 60mm mortar and platoon leader squad. And there is a 2 man (half-squad) stand of "Vanatori di Carri" (tank hunters).
Company HQ. A command squad (3 man), a field-phone team (2 man, prone), and a medical section (2 man).
Arty observer section. A 2 man observer team, and a 2 man field telephone team.
Skoda 100mm howitzers (from GHQ's Italian line). The Romanian army operated some of these, but more of the updated version of this gun (with elongated barrels). I have not bothered to kit-bash the guns.
A battery of 75mm field guns (from H&R's French line). The Romanian army operated a variety of 75mm guns, some French, some German (Krupp), some from who knows who…
A battery of 37mm Bofors AT guns (from the GHQ Polish line). Romanian Malaxa prime movers were actually license-built French Chenillettes (from the H&R French line). These were the AT guns which equipped Romanian mech forces at the start of the war.
I also have a battery of Boehler 47mm guns (from the H&R Italian line). This small gun was the AT gun of the Romanian infantry formations in the early-war period, and stayed on as an infantry gun in many cases through the end of the war.
Late war Pak97/38 75mm AT guns (from the C-in-C German line). These were German-supplied AT guns built by placing a French 75mm field gun onto the Pak38 (50mm AT gun) carriage. Germany supplied these in some numbers to the Romanians. They were used primarily by infantry regiments (mech forces more frequently used the superior Romanian built Resita 75mm AT gun).
My Romanian motor pool is a mix of French, German and even a few Italian vehicles. This is supplemented by some of my Soviet GAZ-AA trucks (not only popular when captured, but also license-built in Romania -- it was originally the Ford Model-A truck, and licensed pretty widely in the inter-war period).
And a company of R-2 tanks (Czech-built Skodas, also known as Pz35(t) in German service, from the GHQ Romanian line). These provide the armored punch in early war service.
Kind of an overview. Romanians are a load of fun because of the great variety of kit. Late-war they can be used as an opponent for Soviet or German/Hungarian forces. Quite a nice addition to my "active forces" box.
Hope that helps.
-Mark
(aka: Mk 1)