Whilst it is indeed handy to know there's a mounted emplacement to your right as you emerge from a gate, by then it's a little too late to do other than say 'oh sh..' as your entrails are scattered to the four winds. Explosive toys...I don't know why, but I had a strange image of Jack tossing a teddy bear through the gate...Perhaps this is just years of gaming experience here, but anyone stupid to be stood right by the gate deserved to be smacked in the head by a fluffy toy packed with C-4.
Personally, given the task of defending a gate, I'd forget the idea of static emplacements. A few tank barricades in front of the gate should stall anyone attempting a Dukes of Hazard style invasion, and any infantry advance could be brought to a halt by a couple of relatively proficient snipers concealed in the hills. As for invaders from space? Erm, some kind of upward firing tank, moving backwards and forwards between defensive positions, driven by a teenager with an infinite supply of cola and an eighties mix tape.
Mix. I'm not sure how familiar you are with ArmA map building, so forgive me if I sound condescending. Maps in ArmA deal essentially with grids. Whilst it is indeed possible to construct an obscenely large map that would take an absurdly long time to get across, and do so without too much of a performance hit, you are forced to sacrifice a great deal of terrain detail. In a completely spaced based map, this wouldn't really matter, as a black space is a black space, but if you want planets as well, then you need to make a choice. Additionally, on a map that big, it only takes so long before the map maker goes completely insane. Trust me. Flibble.
Hang on. The mark 9? Isn't designating that thing a nuke a slight understatement? I'm paraphrasing, but I vaguelly recall Carter commenting that the atmosphere had been turned to plasma. That's just a little overkill in my book, but I suppose it would deal rather effectively with any nearby jaffa. Incidentally, I remember Major Pain was working on a deployable static nuke, similar to the one from the film. I've looked around, but seen no further mention of it. Was it abandoned, or has he squirreled it away somewhere?