my thoughts:, numbered from left to right:
#1 doesn't really look like a missile launcher to me. it has too many 'gun' type features, and honestly looks more like some sort of shoulder fired support laser, or an antitank gun with anachronistic arquibusier style stock.
#2, this is definately supposed to be some sort of energy weapon, but looks rather fragile and puny? plus while the whole power hoses to a seperate battery thing looks cool, they look like they'd be a pain to assemble and base, and would break easy. since the battery pack is pretty small, i don;t see why you couldn't fit it onto the gun itself.
#3 i think is a flamethrower.. but the backpack looks out of place? the weapon seems to have tanks already on the stock, so it doesn't need a backpack tank.. and that backpack doesn't really look like fuel tanks, but rather some sort of techie bits.
#4, not a bad HMG.
#5 the "mortar".. i agree this is probably meant to be some sort of guided missile or drone launcher,. the pad is nice, but i think most buyers aren't going to figure out said figure goes with the launcher.
my thoughts: i think you could go one of two ways here.. i'd take that 'mortar' launch tube assembly and use it on #1 as the rocket launcher. go for a M202 FLASH style look. i would then make #5's weapon a miniature drone on a launch ramp, to make it clear that its a loitering munition type thing.
that said i'd go with this idea instead: i'd actually drop the crewed bit entirely. go for a man portable remote controlled weapon ststation look, with a bulked up tripod and the guns mounted on top with optics and a turret assembly. with enough to build one each of the HMG, laser, flamerthrower, and missile turrets. then make the infantry figures having options for a mix of tablets, wrist computers, and additional ammo containers. basically lean into the higher tech feel of the unit compared to the more traditionalist bulldogs and Grognards