It's not an GW issue. That preety much happens in the stock game or in all the major mods. Things start to become harder over time. Before you know it, the brits will smarten up, and when 1943 rolls around the tide of war
will change.
There are stories about "retired" captains that had been heroes at the begining of the war, completing their tour of duties with very good results. As the war progressed and things started to go badly for the germans, they started recaling these "old salts" back to active duty in hope of turning the tide. Sadly, some (if not most) of these famous captains were sunk (by aircraft mostly) on their very first patrol upon return to active duty
.... such was the diference between the early and later years.