I really don't like MG spam...particularly against OKW. There are better ways. I just played two matches against higher-ranked Soviets with my OKW (They were 1750ish, I am 2000ish). First match, the guy built 7 MGs (La Gleize Breakout). That may have been because I capped three of them.
Second match (Angoville) my opponent built at least three an MGed the houses on the right. So? Have the right. I'll take left, build LeIGs to make you cry, and then Command Panther and KT. I lost a Luchs, but then he lost two T70s and a AATruck in return. Then my heavy tanks wrecked his T34 spam (four or five T34s killed, no losses).
So what do I fear when I play as OKW from the SU? Well, Shocks, for starters. They make mincemeat out of my guys. Also, a decent use of T70 or AA truck (don't attack shrek blob ON it's heal base). Finally, Katyushas and Tank Destroyers. Oh, and kill the Command Panther before the King Tiger, don't primary the KT.
Yeah, there are a few things that one shouldn't do... Seven Maxims is spam and it's too much. Three is the most I usually build (as you can see in the replay). Below is a replay of me playing against a couple (or three?) Maxims. I was surprised, actually, at the quality of play on the Soviet's part. You can see the ranks in the replay thread.
One thing to consider is that build orders, player knowledge, and skill vary widely between the top twenty, fifty, one hundred, two hundred, etc. For example, in my replay against Choccy on Minsk, I went Maxims into SU76 then IS2.
Most people in the top 200 don't build 7 T34s against a player of equal skill. OKW is quite strong now, and they have a lot of options to apply mid game pressure against the Soviets.