So I get two ships every time I build one... and this is fair how lol? The HP reduction is a potential issue, but being able to spam out fleets virtually at will in the early game is ridiculously OP. As long as you stay on top of tech, I see no reason why their HP issue would present any kind of problem, ever.
Add in the pop replacement rate, and I can cover up the galaxy in constructors and colony ships. Then my colonies seems to instantly gain citizens, and the pop cap keeps food under control, so... what exactly are the real downsides to running these guys?