The Vasudans have done pretty well all by themselves, look at the Hecate compared to the Hatshepsut, as for Zod capital ships
But they have very good corvettes and they destroyer is actualy superior in many wais to the terran Hecate. More HP, more powerefull beams good AAAF defences you name it. I would much rather go into battle with a Hatsheepsut then a Hecate. It just makes me feel more secure about its chances of surviving an actual engangement with shivan warships. Cant say the same about the Hecate.
You do realise that the Hecate is obviously not meant as a ship of the line? In spite what the database says [which is hazy to say the least], the Hecate is closer to an aircraft carrier than a battleship, moving away from the duel role of the Orion and focussing on the ability to project its firepower across a system. The term 'flagship' does not instantly denote the ability to go toe-to-toe with modern Shivan warships, but rather to hold the commanding officer and serve as the central part of a given fleet.
The feeling I get, is that while Vasudans are preferring to stick closely to the old style of Fleet composure we have seen since Freespace 1, centered by a large ship somewhere between Carrier and Battleship, the Terrans have instead begun to create ships more suited to singular tasks, rather than being a jack of all trades, master of none. The Hecate gives up brute force for more fighters and C&C Components, leaving the brute anti-cap force to the ageing Orion, soon to be replaced by the pocket-battleship that is the Deimos.
Just because the Hecate can't go up against a Shivan warship with the same voracity that a Hatshepsut can bring to bear, doesn't necissarily mean the design is a failure, and to think so is to simply be presumptuous.