The reason this is being posted in the PvP forum is because of how this issue negatively affects the Republic in ranked warzones, and contributes to why Commandos (and to a lesser extent, Vanguards) are not picked up in ranked warzones.
The reasoning behind this is very simple. The entire Bounty Hunter class is stronger than the Republic Trooper counterpart because of the way that the resource system has been handled. The other option is to buff the Trooper, but why give up an opportunity to nerf Mercenaries?
The Trooper has high ammo regeneration for 4 ammo, which is 1/3 of the total ammo pool (12).
The Bounty Hunter has high heat regeneration for 40 heat, which is 2/5 of the total heat pool (100).
As many people may notice, 1/3 =/= 2/5.
As a result, Bounty Hunters have a total of 7 more heat to use. 7 heat is not enough for any ability to be cast, it does allow for easier management of heat. Not to mention that 1 ammo is equal to 8 heat (which favours the Bounty Hunter) unless a direct % comparison is available (33 heat fusion missle, 25 heat flame thrower).
A Pyrotech Mercenary casts power surge followed by fusion missle. They can then cast rail shot when the GCD is done and be left with 36 heat (0 + 33 = 33, 33 - 5 = 28, 28 + 16 = 44, 44 - 8 = 36) and be in their high heat regeneration zone.
An Assault Specialist Commando that casts tech override followed by plasma grenade and then a high impact bolt will be left with 7 ammo (12 - 4 = 8, 8 + 0.6 = 8.6, 8.6 - 2 = 6.6, 6.6 + 1 = 7.6). They would then be in their medium regeneration zone. They would then regenerate 0.36 ammo and be left with 7.96 ammo and be in medium regeneration for another second.
These examples do not even touch upon the implications of a longer fight. The reason is that two Bounty Hunter 16 heat abilities = 32 heat, two Trooper 2 ammo abilities = 4 ammo which would equate to 33 heat. This would result in the Bounty Hunter getting more casts in a longer fight using the same rotation. Whilst this would rarely happen in a PvP situation, it is still a factor in the class balance.
There are two simple solutions to this mirror class imbalance. The first is to reduce the high heat regeneration zone to 33 heat. The second is to give the Trooper high ammo regeneration until 5 ammo (5/12 ~ 42 heat) which would dramatically improve the discrepancy (2 heat compared to 7). The third solution is to give both classes the same resource system. Since it has not been done in over a year, I doubt it will be done now.
EDIT: Thanks to Holmes.
His two videos to help prove the imbalance.
EDIT 2: Dr_Kid's thread:
EDIT 3: Dr_Kid's method:
The longer the test, the greater the disparity will be. That's why my test is ideal. Two button rotation.
Ion Pulse, Hammershot, Ion Pulse, Hammershot, Ion Pulse, Hammershot, and repeat.
Count the number of Ion Pulses until you're unable to use another Ion Pulse. Repeat two more times to account for lag.
Flame burst, Rapid shots, Flame burst, Rapid shots, Flame burst, Rapid shots.
Count number of Flamebursts until you're unable to activate it again. Repeat twice more to account for lag.
Compare the results.
I thought I'd post this as I play a Commando and I'm sick of Mercenaries complaining when they have it so well off. That, and people seem to be too pre-occupied with bubble stun and smash to even notice this issue.