These ships are pretty small if you look at what is represented by most of Sci-Fi out there. The biggest ship shown above at 115m is smaller than the Corellian Corvette (150m) from the opening scene in Star Wars which fits inside the Imperial Star Destroyer Hangar.
But believe me this is not a bad thing, especially if we are expected to wire, pipe and bolt everything down. As it is, I think major ship damage will take a long tedious effort to repair manually, smaller ships like fighters will be hard to hit, easier to repair and yet wreck havoc for bigger ships that are not adequately defended. Players will need to design ships with this in mind, the larger ships will likely be very complex and weaponry, cargo space and power will have to be carefully balanced. No Star Destroyers or USS Enterprises in this game. Ships designed with pointless rooms full of conference tables, kitchens and bunk beds seems very unlikely. Whatever space not occupied by corridors and ship systems will be used for cargo (hauling extra ammo, spare parts and additional resources). All things considered, a combination of smaller ships would be preferable. Even for large factions, I expect armadas of medium sized ships rather than huge titans because they are less of a target, can move independently of one another and are much less complex to repair and maintain.
Huge ships, unless you have a literal empire supporting you are just not practical outside of maybe the intimidation factor but I think it would end up being more of an enticing target. Most players will probably end up in fighters, simply because they are single pilot, simple up-keep, disposable and can put out some decent damage (simply put, more fun for those with short attention spans). Large ships will need a dedicated crew to keep operating at peak efficiency which will probably get boring for the crew between activities. Fights will be costly for the bigger ships as they'll have a lot more that can be broken, not to mention the risk of losing much more should they fall.