I'd guess its just an oversight for Buzzsaw. Before submitting a terrain the designer has to edit plane assignments for each field in the terrain editor. A default button in the TE removes planes except the Storch from V fields and ports, as well as PT boats where there are no spawns for them and so on. Then its a matter of manually editing out the RV8 and also the 163 except at three fields. Every time a new ride is added to AH then someone at HTC, probably Skuzzy, has to re-edit these files for each MA terrain in order to include it.
So it is possible that at some point someone mucked up the file for Buzzsaw and those rides were not disabled at V fields and ports. The other possibility is that the default field assignment routine in the terrain editor is bugged and is not excluding the I-16 and Brewster from V fields and ports like it should. In which case other MA terrains might have the same issue.
