I would agree that the Mass Cloning Ship would be like a logistic ship for a massed planetary invasion. Take this scenario for instance. The SAoY wants to invade a hostile planet. First it goes in send in its special forces to undermine them and whatnot, then the main fleet comes and engages any defense fleet and automated systems, and then bombards the planet from orbit, then what if it is needed elsewhere. Like an old enemy knocking on the backdoor. So after the fleet has taken away the planet's ability to strategically fight, they would dash off to handle th situation in another sector. But not before leaving one of their Mass Cloning Ship either in orbit or landing it directly on the planet. To either 1) Destroy/subdue the enemy by attrition 2)Holding the planet and enforcing the population. But of course to save money, all their equipment will be second-rated, not top of the line. Top of the line would only be reserved for true Nekos. They would be saving money and not risking Nekos lives, and at the same time destroying resistance by attrition.
Of course the ship would have defensive armaments and shields. But immediately after landing perferably near a body of water, they would establish a buffer zone around the ship. They would also have the intel from the previous invasion on enemy weapon's range and capability. BUT if this is already out there in some form, that would be the tru answer to why we don't need a Mass Cloning Ship.