A big thing in this game as allies as well is to keep German and Italy with as low of an income as possible. I know that sounds obvious, but it is harder said than done. Do NOT abandon Karelia! That is a terrible idea. UK1 can land 2 figs there along with 2 extra russian inf being built giving you 11 inf, 1 art, 1 arm, 2 fig, 1 AA gun. Following on UK2 they should begin landing atleast, but with luck more, 4 ground units a turn there. Yes G can take it, but that stack will be destroyed the following turn by the UK. US should be in africa at the end of turn 2 in force. Do not let Italy get both of her NOs for more than 2 rounds, do not let Germany get 3 for free. If you SBR, do it to Italy first. Germany can only build 10 units a turn (unless they buy an IC) and rely on Italy to stack france with INF. Be sure to threaten atleast 2, with luck 3, imporantent territories with drops (usually france, italy, and berlin). And try to get russia her 2nd NO by turn 4 or 5 so they can afford to hold off the Japan monster.
One purchase that works well for me on R1 is 6 art 2 inf. Place the inf in Kar, art in moscow. On R2 buy mostly/all tanks, move all moscow and karelia forces into Belorussia and put a good stack of units into Eastern Ukraine. Typically you will have on Belo: 13 inf, 8 art, 1 arm, on Ukraine 4 ish inf. Plus your 6 arm in back may force the Germans to pull back (doesn’t always work depends on G’s purchases, but that is alot of Russian punch has odds vs 15 inf 10 arm or 5 inf 18 arm), and if you get the Germans out of East Poland that is always a very good thing.