Bleh, became a bit more of a wall of text than I wanted it to be. Basically, you can get some pretty good range out of the GBU-39s even from the A-10C.
I think you’re underestimating the range of these glidebombs, yes even from the A-10C. These wings do a lot of heavy lifting when it comes to range. At sealevel, going 600-700kph, the A-10C can still get around 6km of range out of these bombs, a JDAM however only gets about a 2km range in comparison.
I tested it just now, you need between probably around 2.5km of altitude in order to outrange Pantsirs, so for 20km range. So it’s not that extreme. At 2km I managed to get a range of around 16-17km, at 3km altitude it had more than enough energy to do 20km.
Problem really is the flight time, altitude doesn’t seem to matter much, but it’s around 2.5 minutes for 20km, which is kinda really unuseable. Even for SPAA, it’s unlikely they sit completely still for that long. Especially considering US teams, it means you potentially lose a lot of ground, giving enemy SPAA room to move. It will definitely not be great, but it’s doable. With a faster launch speed, like with the F-15E you could cut down the flight time well in half, which is much more useable.
Climb time to around 2.5-3km altitude isn’t too bad. Maybe a 1-1.5 minutes or so, with some extra to regain speed. But it’s comparatively pretty bad, and usually you don’t have the luxury to spend much time in GRB anyway. A lot of my matches end in around 10-15 minutes or so, and spawning CAS may only happen much later in the game.
Anyways I myself can’t really imagine using the A-10C that way. Never did that. I always used it treetop level at <6km away from the battlefield in order to cut down on ammunition flight times, can’t be any further because the weapons lack the range, can’t be any higher at those ranges due to SPAA. Outranging on the other hand just come with too large flight times to be effective.