Lecic
Convicted Lancake Abuser
Look. You obviously don't understand how block grids work. You can't have them be part of the same entity and have it move separately too. To move on its own, it needs to be part of its block grid, and that requires it to be it's own entity. The best you can do is glue two grids together at a connection point (turret points, docking points, rails in the future) and make it so there are as few desyncs between the two as possible.I still consider it the best option. It provides more freedom to building ships with turrets than any other option thus presented.
In addition, it would greatly reduce the entity count on ships in general, which would be amazing for performance problems in that area.
Space Engineers does the exact same thing. Ships are each their own grid, but you can link them with things like landing gears, rotors, pistons, etc. They're still their own entity and block grid, though.