What most WWII fighters do have is an asymmetry in the vertical tail assembly. In the case of the P-51, the leading edge of the vertical tail is offset about 1 degree to the left if I remember correctly. Most WWII fighters compensate with an offset to one side or the other like the P-51 example. The direction of offset obviously depends on the prop direction. An alternative method is employed for example in the case of the Messerschmitt Bf-109: the asymmetry is built in by using a cambered vertical tail where one side of the vertical fin is thicker than the other side. You can pick up any high quality drawing (such as those by Arthur Bentley) if you want to confirm these offsets/asymmetries.

The fin offsets on WWII aircraft have the same purpose as the side thrust offsets of our models. Of course, the asymmetry is not enough to compensate for all the effects when you suddenly throttle up, or when you rotate the aircraft, so you still need to use a lot of rudder during take-off and landing on the fullsize aircraft. However, what the offsets do achieve is that the rudder end up approximately center when the aircraft is at cruise speed with a cruise throttle setting.

Of course irrelevant to the discussion, but that is a pretty wild statement