you’re correct, they do not strap guns to improvised attack drones. they’re not necessarily single-use either, though. A kamikaze drone will detonate its payload while its still attached, which is an option. There is plenty of footage of IADs which use a servo to just physically drop a payload onto targets from above, and those could potentially be used over and over. I think the kamikaze version is able to be more effective, for a variety of reasons, but both versions seem to be seeing use.