If you've actually played 1s, you'd see how they are at a disadvantage. This is a general consensus among most of the high level players I've played. Further, coh2chart.com also shows that on average, OKW wins almost 20% less than allied factions in 1s. This clearly is not limited to individual skill.
I've played 166 1v1s as OKW (granted that I haven't played them in about a month or so) and 200+ 2v2s as OKW. Last time I checked my 1v1 ranking for OKW was about 500, before the leaderboard started hiding ranks after 2 weeks.
Its a mix of both individual skill and minor issues. I can't see non-doc MGs combined with T0 AT from raketens and schrek Volks being a balanced combo tbh. Or if a non-doc MG was added to OKW, USF would HAVE TO receive a mortar in T0.