Kallistra has 12mm early war figures including Russians and AustroHungarians. It's a great range, I bought enough French and Germans to do a couple of divisions per side thus a corps for the rules we play. Not interested in trench war just the opening few months.
We play grand tactical though so don't need the MGs - just the infantry.
I also like Blue Moon's 18mms - I've painted up late war French as Italians and late war Germans as AH opponents to do a very undergamed theatre in that war. And yeah, the Italians usually get thumped trying to attack on the Isonzo. But so did the real ones.
I do wish Great Escape good luck though on their range!