@Caimheul1313
"You can't assume anything outside of the context of the question. Nothing requires me to take the Armament upgrade if I take Pathfinders, just as nothing requires me to take more than one Pathfinder unit. If I don't plan to use the Pathfinders as an aggressive deployment, or as an early sacrificial unit, then I don't HAVE to take more than one. I also don't HAVE to fill the heavy slot.
Z-6 Trooper + 1 body on a rebel trooper unit would be better since it can be used every turn without requiring a recovery and is the same range as the default weapon on the unit, so no "hidden tax" to allow the rest of the unit to engage the same target. Plus it adds two wounds to the unit instead of just one. Or any number of other combination of upgrades that can be purchased for other units using those same 32 points. There's lots of better ways to invest 32 points than in a single model with an exhausting weapon."
Z-6 + Trooper adds 2 wounds (so, +1 wound is good...but those wounds are less effective than a Pathfinders because they have white surge dice without Danger Sense, but they do have access to Nimble...but that requires an action before someone fires on the unit...so definitely not as good compared to say, Pathfinders with Duck and Cover which grants the same effect on demand AND the extra white die).
Total damage increase is only +2 (1.125 hit, .875 crit) at ranges 1-3 vs the 2.125 from Bistan (1.5 hit, .625 crit) at ranges 1-4.
Given that the entire Pathfinder squad can engage at range 4, this increases the survivability compared to the Rebel tooper squad, and Bistan can engage sooner than the Z-6 and extra trooper while suffering less overall danger.
Summary: Bistan is a better upgrade.
I agree, there are plenty of possible combinations, I just don't see a lot of upgrades 'for other units' (important caveat apparently) that are providing more than Bistan does, exhaust or not. (again, exhaust for a range 4 weapon just means the unit is unlikely to move and fire, but at that range it also probably doesn't have to).
@MasterShake2
"Reminder, the whole unit, including Pao shoots at range 4. I'd also say Pao is better at 22 than Bistan is at 32. To each his own."
Right, it's not like Pao or Bistan's dice are forced to fire separately (unlike say, the HH-12 or DLT-19) from the rest of the unit. I'd still prioritize Bistan before Pao for the extra firepower, but I also think I'd deploy them using the long range config as fire support for the 3rd pathfinder unit and Jyn (since they all have to be deployed at range 4, it's very very likely I'd only put the scout 1 upgrade on the non-Pao/Bistan unit so it can move into position somewhere at range 3 of the nearest Imperial unit, and the short range config.