Trool, Welcome to SUBSIM!
I am a dev on the surface warfare mod, and as far as I know (I do all the 3d editing, along with a couple other skilled individuals) We have not yet figured out how to make ships follow other ships. the simplest thing to do is make the other ship the enemy, but that wouldnt be much help eh?
as far as I know, we are basing the campaign around full-on real battles, that you get to take part in, in campaign, and single missions.
these battles are going to be set up to where your command is historically in it, but, you get to choose your conduct in the heat of battle, and fight to survive.
some campaigns will require your skills as a wily captain of a merchant raider, closing in on your kill and dropping the hatches and opening fire.
some may keep you attached to a convoy, attacking submarines as they are detected
Either way, we are sure you wont be disappointed when TSWSM releases as a full mod, the beta is due aug. 20