Well, the ASW Ancient ships are based of the design aesthetic of the iNFR1 Ancients, which in turn are built around the Knossos Aesthetic.
The INFSCP Ancients, some of which are in ASW (ie. the Malia and the Minos) have the big "gas sack" thing and look appreciably different.
I rather like the Knossos-inspired designs - if they were made more grungy and mechanical, they'd look less like "tame shivans" and more like actual shivans (at least the FS1 ones). As they stand right now I think they stand at a good balance and you can see similarities with the Vasudans (which goes with the vasudans-visited-by-ancients theory).