Maybe not that, but the ships in the Reef were rather massive. Of course not the same but maybe similar.

Any sustained space combat is going to need some form of resupply for fuel and armament. I don't think humanity in Destiny has the necessary resources, manpower or even knowledge to be able to build such forms of resupply. And since the jumpships appear to be fighter-class, it's unlikely that they are self-sustaining. Not to mention that we don't even know if the ships are even armed.