Usually we see the enemy planes as a dark silouete when aproaching at their dead six, mostly the same in a HO, or scissoring quickly side by side. So we have few or no chances to apreciate their art details. On the other hand, everyone wants to have its own plane as much detailed as possible.
How about separating own plane detail level from the rest? So we can have very hi-res textures and 3d model for own plane and very low-res textures and 3d models for any other plane or vehicle (or ground object).
And how about having two separate detail levels to configure: air (activated when we fly) and ground (activated when we drive vehicles or boats).