I know official patrol (as per GW) is light cruiser with a pair of escorts, but you are correct in that I mean't far flung patrol fleet with strong pirate presence, thus lots of ordnance to flush them out of their hidey-holes, and escorts to wipe them out. The light cruisers and frigates are known for their "long legs" and thus can patrol for long lengths of time, making them ideal mainstay vessels for this fleet. I feel it is not appropriate to have lots of dedicated line ships, so the fleet does not include such things as tyrants, gothics or dominators. As for the lots of ordnance, it is rather steep compared to imperial standard, but the loss of direct fire, no NC and the fact that IN ordnance is really bad kind of makes up for it.