Just going to provide a couple of tips for this particular mission:
1) The Missouri is a juggernaut out on the naval battlefield and can fire across the island at targets. Do not be afraid to have the Missouri go into battle while leaving the JQA sitting in a support role. Make sure to upgrade it as often as you can to give it an unfair advantage on the battlefield.
2) Support roles will help clear out some tricky spots when trying to get into the large complex in the middle, or when trying to secure the beach head at the end of the mission so utilize them.
3) Always carry a shotgun. There are quite a few thugs roaming around this mission and if you do not have the tools to put them down quickly they will overrun you.
4) Grab the railgun for the final objective in which you must destroy the three alien transmitters. There are a few sniper units position between you and the beach head as well as some tricky encounters should you find yourself out in the open.