First off, by adding rapid shots you are simply subtracting from the numerator of a fraction (heat loss/time) thus making your ratio of those fractions (vanguard/merc) absurdly high. It simply doesn't help your cause when you inject math distortions like that and then trumpet the result, "Vanguards use 66.6% more resources than Mercs" which fails everyone's basic understanding of the matter. It's like claiming that wine has 10x the alcohol content of beer - if you first extract a fixed amount of alcohol from each fluid.

Secondly random lag doesn't affect both characters equally. It affects the mean (average) performance of each character equally. That is a statistics distinction which you may not be aware of. But your testing methodology is specifically vulnerable to random white noise, for reasons which I will try to explain. The basic segment of your test (FlameBurst + Rapid Shots) has almost NO measurable heat usage (1 unit). Over those two GCDs, your timing loss can easily be 0.2 seconds, which causes heat dissipation of - yes, 1 unit! Thus a common level of variance can completely disguise the very metric you are attempting to measure. That is why a test consisting of basic segments with a higher measurable heat usage, such as I used, are inherently more accurate.

Yes, you could get more accuracy by running the tests repeatedly. But using your methodology you might literally need to do it hundreds of times because the variance is so high relative to the mean of the metric you are measuring. Good luck with that.

Sometimes, no matter how hard both people try, it is not possible for the person taking the other side of an issue from you to prove that you are correct.

I did a manual run-through of the situation to eliminate any white noise. I put it in spoiler tags to save space (there may be errors). The assumptions I made:

0-39 high heat regeneration, 40 - 79 medium regeneration, 80 - 100 low regeneration.

12 - 8 high regeneration, 8 - 3 medium regeneration, 3 - 0 low regeneration.

Bounty Hunter:

Cost: 16 heat

Regeration per rotation:

High Regen: 15 Net: 1 heat

Medium Regen: 9 Net: 7 heat

Low Regen: 6 Net: 10 heat

Trooper:

Cost: 2 ammo

Regeneration per rotation:

High Regen: 1.8 Net: 0.2 ammo

Medium Regen: 1.08 Net: 0.92 ammo

Low Regen: 0.72 Net: 1.28 ammo

After 24 rotations the Bounty Hunter will have 24 heat, he will drop into medium regeneration on the 25th rotation (24 + 16 = 40). There will be 1 second of medium regeneration followed by two of high regeneration, net loss is 3 heat (27).

Rotation 26 (27 + 16 = 43) will have 2 seconds of medium regeneration followed by 1 of high regeneration, net loss is 5 heat (32).

Rotation 27 (32 + 16 = 48) will have all medium regeneration (39).

After 31 rotations the Bounty Hunter will have 67 heat, he will drop into low regeneration on the 32nd rotation (67 + 16 = 83). There will be 2 seconds of low regeneration followed by 1 second of medium regeneration, net loss is 9 heat (76).

They will get one final rotation before having too much heat (76 + 16 = 92). Result is 33 full rotations and 86 heat left.

After 10 rotations the Trooper will have 10 ammo, he will drop into medium regeneration on the 11th rotation (10 - 2 = 8). There will be 1 second of medium regeneration followed by two of high regeneration, net loss is 0.44 (9.56).

Rotation 12 (9.56 - 2 = 7.56) will have 2 seconds of medium regeneration followed by 1 of high regeneration, net loss is 0.68 (8.88).

Rotation 13 (8.88 - 2 = 6.88) will have all medium regeneration (7.96).

After 17 rotations the trooper will have 4.28 ammo, he will drop into low regeneration on the 18th rotation (4.28 - 2 = 2.28). There will be 3 seconds of low regeneration, net loss is 1.28 (3).

They will get one final rotation before having too little ammo (3 - 2 = 1). Result is 19 full rotations and 1.72 ammo left.

As you can see, the Trooper gets 19 rotations. The Bounty Hunter gets 33.

33 > 19.

I'll assume the difference in values (from the real-world tests) is due to the white noise. There is still a substantial difference though. Feel free to point out anything that is inconsistent.