Who made the Aten during the Great War? And then on top of that, kept using it through the second?
and on top of THAT, built an almost same-level useless cruiser on that?
Now which race made the Fenris...and then muscled it to the Leviathan, and then created the holy terror of most fighter pilots, the Aeolus? Now, compare the losses of Aeoli to that of Fenris and Leviathan cruisers. I'd say that more of the latter were lost, in ratio, than the former. Also remember, a significant number would have been lost To the NTF! NOT to the shivans, so you really can't claim the 20/24 loss thing, since I bet a significant number actually betrayed the GTVA...
Besides, the Vasudans are evil!! Why else did Bosch create the NTF? He obviously found out some big secret they were hiding and decided to kill em off while we still had a chance!