Now, if loadouts in other mods is brought up, Blue Planet would be a good candidate for discussion.
In this case, the Myrmidon becomes quite awesome due to the Balor. Load all primary banks with the cannon and dump all power from guns into shields and engines. Even with both banks set to fire, the ROF is still spectacular and power usage is so low that you can just keep going... Given the nature of BP you probably want to fill the secondary banks with Trebuchets to neutralize the sudden (and often) beam turret threat that likes to arise. This setup will actually work well for you on "Universal Truth," which must be one of the best-made missions I've ever flown (despite the bugs).
Regarding the Myrmidon, I've noted many people saying that you can load it with the Maxim. Unless there's an exception for dogfights, this just isn't true (unless you've got a modded Myrm).
-Thaeris