Well this is a comon problem... it is not easy going after turreted craft.
Make sure your wingman Hypers out fisrt, he is invunerable, and can fraw the fire from one of the shuttles.
Make sure you have a full load of Torps, and sheilds at 200% before you go to this place. What i did that worked somewhat well, is angle my shields back, and link ions and lasers. I go in with lasers blazing and as soon as the Shuttle turns away (heh imps dont like playing chicken) Deadfire 2 torps at close range. If at any point your shields fail, angle the forward and you will have a fresh 200% to help you out.
You might be banged and brused up, but at least you now can easily pick aawy at the convoy.
Go after the Chined cargo ships first, and take out the engines.. they wont go anywhere after they lost thier engines. Next go after the other transports.. they are weakly armed and should be easy pickings... once you finished as much as you can.. go back.. re-load, and finish off the remains