Yes, this is your standard 'overthinking-stargate' post.
But given that the main rival to Jaffa and Goa'uld forces would traditionally be other Jaffa and Goa'uld, the primary (or secondary, second to policing civilians) threat would come from air assault and assorting air-support, given that Ha'tak could land, or bring gliders or both, and Al'kesh could show up independently of Ha'taks and gliders, you'd think that Jaffa would have ample air defenses. But as far as we've seen in the show, they don't.
What would complete the setting in that regard? Should they have had some sort of MANPADs? The ring-threading round gliders seem like the obvious choice, but they do not apparently make them as they once did, for some reason.
I like that we don't see a lot of defense in Goa'uld technology. They believe that the only threats to them will come through the gate network that they (until recently) control completely.
Their weapons are purpose built to oppress slaves.
Their chief forms of defense, when truly threatened, are retreat and burying a wormhole.
It makes Stargate one of the most plausible "humanity resists advanced aliens" plots - because the Goa'uld are caught on their heels, tactically by Earth's wormhole being activated by humans who shouldn't have found it and (the Goloa'uld thought) shouldn't have had the wits to activate it.
And things get strange as the Tau'ri are strangely good at war for having such a relative disadvantage regarding technology. Tau'ri weapons and tactics at the start of the series should not be effective and the development of Tau'ri technology is shockingly rapid and produces novel results.
The Goa'uld keep bringing knives to a gun fight while the Tau'ri started with a BB Gun but keep bringing better guns.
We'd been killing eachother by the millions for thousands of years 8)
nowhere else could you find so many people who'd butcher eachother like that
In S1E2, teal'c and O'Neill fail to sufficiently damage a glider with staff weapons, but a well placed stinger takes it out.
Presumably a tower based staff cannot can take out a glider, but the Taur'i came prepared with stingers, claymores, C4, and a boatload of tenacity and guerilla tactics.
Their use of manoeuvring and deception is one of their most valuable traits, easily beating muchvstronger Jaffa forces, which rely on force and numbers.