Just an Idea i use this on my mechs but why not turn the area H-05 into rocket or missile launchers in theses areas. Sure its a more heavy load but its worth it because air-craft don't become an issue anymore.
You've changed Helldiver's desing, I see (yes, I'm completely not intrested in mech, Helldiver's my true obsession for now). Behind his neck is it a sword\long knife? And what is it on his legs - package of magazines? And why is the pistol strapped (I guess it's the right word) to his chest instead of his legs where the magazines (or whatever it is) are?
And also: Helldiver suit inspired me to create my own in form of literature - I should thank you, Theo, for that. You (and whoever is intrested) can take a look here (also, there is a russian version available).