I'd say the destroyer count would be about 40 destroyers, for the entire GTVA (Terrans and Vasudans). Hey, I had a great idea, how about a fleet breakdown! (I love these
)
GTC Fenris - about 40 or so
GTC Leviathan - about 20-30 or so
GTC Aeolus - 24+ (confirmed by database, but the NTF may have made more)
GTCv Deimos - ~30
GTD Orion - 15
GTD Hecate - 5
GTVA Colossus - 1 (duh)
GVC Aten - probably 10-20 (destroyed by former GTA, mothballed)
GVC Mentu - ~20
GVCv Sobek - ~30
GVD Typhon - 15
GVD Hatshepsut - 5
So for the GTVA, they have:
Cruisers - 84
Corvettes - 60
Destroyers - 40
However, after the NTF rebellion, this many ships are left (not only defected, but destroyed by the NTF too):
Cruisers - 36 (32+16 defected or destroyed)
Corvettes - 43 (11+6 defected or destroyed)
Destroyers - 25 (10+5 defected or destroyed)
I will admit that these figures are almost pure speculation.