It depends a lot on the amount of objects you expect to have and the platform in which the game will be running. But it will surelly have an impact if you're expecting to have ship swarms like in Starcraft, for instance.
You could create the sprite dynamically, but I don't think you can do that inside Construct. You'd have to have the parts on your server, create the png, store that online (maybe a blob in a db) and load the external file.
Still, I don't think you could get away with creating the collision boxes this way. As far as I know you can't load a collision box in Construct.