Love to hear the logic behind that. Hard data that shows how often factions win and lose obviously doesn't reflect their relative overall strength - right?
Despite the immense amount of hard work by Paid_Player that goes into producing these infographics, the fact of the matter is that what is displayed are just simple counting metrics, nothing more. Having an in depth discussion with him and minds much brighter than my own over this, the main take away was: although numbers don't lie, people do. I think people have jumped onto the "I'm being quantitative, therefore my argument has more validity train" without actually properly thinking through what these numbers represent, and without recognizing that these "statistics" belay the actual nature of situational, unit, and player behavior. Furthermore, only measuring 250 players doesn't give a very representative sample of anything, not to mention it fails to represent players playing within the same bracket. A lot of the ladder is top250 bodying those in the 500--1200 range, which is... suffice to say, a disparate skill gap, and really should not be used objectively as evidence of balance.
To address the topic at hand, I would tend to stay away from the UKF and the Wehrmacht until you have learned some core tactical theory, ie. fire and maneuver and unit preservation, since mistakes are exacerbated and one slip up can lose you games, and your sanity. Once you have a better understanding of the "phases of the game" unit timing , map control (these are especially important if you would like to play as the relatively static UKF) and pressing you should sit down and ask yourself how you like to play, what is your general posture and strategy? Which units and situations do you excel with?
As a general rule of thumb, with the USF, you can be overwhelming and press high up the map like a demon, and so long as you preserve your units, maintain the pressure across as broad a front as possible, and time your teching correctly you should have success. The OKW are flexible, but require you to "read" your opponent and then make the correct decision to adapt to your situation at hand. The Soviets are similar but reward executing a plan more so than the OKW where you can freestyle a little more, I would consider the Soviets to be fairly rigid in their stratagem.
Also, PanzerGeneralForever makes a very strong point. Given the congested map design in team games, defensive factions get a natural force multiplier that they would not have had in a 1v1-- an arena that can be very difficult considering more mobile factions will run them off the map.