If you commit to a strategy, of Control over the Ukraine, and Novogorod, coupled with a factory in Romania, you should be able to simply OUTBUILD the Russians until the game is over, as long as you can keep your income relative and increasing.
13 units a turn will put them down, and you’ll have a few extra resources to defend europe with.
That said, building 50/50 inf and art, isn’t viable. The ratio should be different. You’re going to losing infantry, and having artiller around with nothing to support, doesn’t help anyone but your enemy.
I suggest 6 inf 4 art save a buck for something else. If you have the money, you should also be building an aircraft unit everyturn. A fighter OR Bomber.
My other favourite is this… 3 inf UKR, 1/2 mec 1/2 arm ROM a slow stack build in UKR, with reinforcements in Berlin, trickling in via the baltic.