Think about it this way:
At the start of the rebellion, the NTF had enough warships and fighters to slug it out with the GTVA. However, by The Sixth Wonder, the NTF has resorted to guerilla tactics because they lost many good ships. By Endgame, they only have the Grall, Alexandria and Iceni.
Blue Lion, try using common sense instead of attempting to figure out canon numbers. I assure you that the former will make you feel much more satisfied with your mod instead of trying to figure out canon and sticking to it (because I did that to the Lucifer in TSM-69). Use FS2 canon as a reference, but for the sake of Bosch, don't adhere rigidly to it. Since AG deals with the beginning of the NTF, you should give them enough warships to duel it out with the GTVA and either reach a stalemate or be victorious.