I see all the patches nowadays use ar2_fire1/2/3 as the AR2's fire sound instead of ar1_1/2/3 like it originally is, but is that the right choice? Sure, the ar2 sounds are all labeled as ar2 in the ar2 folder, but Valve still used the ar1 sounds for it even in the E3 2003 Prison demo. Maybe they just didn't have time to change the sounds, but let's take a look at the sounds' metadata:
ar1_1
ar2_fire1
While sound metadata isn't reliable because a sound made at a previous point in time could've been accidentally resaved at a later point in time (basically, the same issue with the .vmf's in the WC Mappack), they can still act as a "Last Modified" date for the sounds.
In this case, ar1_1 is last saved in 2000 while ar2_fire1 is last touched in 2002. It's possible that they forgot to change the sounds despite the 1 year time frame between the creation of the ar2 fire sounds and E3 2003 (similar to how the Combot still uses the Wasteland Scanner's hover sound instead of the one in its own folder), but it's also possible that Valve chose to stick with the ar1 sounds intentionally. Thoughts?