So far, I'd say that only ships smaller than capital ships will be viable. There may be some capital ships as flagships just to show the power of factions, but they wouldn't really be used for combat.
Being small or just a fighter with oodles of armor seems to be most effective right now. Maybe once we have flak cannons, the tripod mounted weapons, and some adjustments to make giant fighters not as viable, then we can see multi-crew ships.
Another thought, It may be that those non-capital/non-fighter ships might work as very special purpose craft. As in, they might be good for supporting a large contingent of fighters with fuel and ammo, or carrying many torpedoes and rail cannons to destroy stations, or they might only be suited to destroying other ships of similar size that don't have a fighter escort.