I've been playing the COH series for a while now.

COH 1-st wast fine because the factions had basically the same level units.
As of COH 2: It was good at the beginning, but they also wanted to make more money so they did the DLC thing.
And every faction that the DLC- brought where OP. The did fix it. But now at in the end it is unblanced and you are most likely to lose, if you play axis.

The gave the allied troops to many perks.