That's certainly true - Armada dogfights in the strategy mode are one thing, but an extended battle against multiple waves like in the gauntlet is something else entirely. Personally, I've never been able to get as far as the heavy fighters on either side. On the Terran side, I never got past the last of the Phantom missions, and in fact, maybe this gun range issue is the exact reason I've had so much trouble with that...
I really do wish there was a little more story to Armada, incidentally. It was a low budget game, I know... but just imagine how much cooler (and more popular!) it would have been, if instead of simply having a fifteen mission gauntlet, it would have had the exact same missions presented with WC2-style talking head briefings/debriefings and short between-missions scenes. Just WC2 quality would have been fine - heck, take the exact same art, paint a moustache on Blair and dye Angel's hair blonde to make them into different people, and no voiceovers. The Kilrathi, of course, would have required a little more work. But how awesome that would have been! The depth it would have added to the Kilrathi especially...