I think it is rather odd that we stopped using the Brawl Index, even though it is just a scaler multiple of Brawl's damage to using a scaler multiple that is approximately based off a T1 blast. Do we know what power the dmg scaler is actually based off of?
The damage scalar comes directly from in-game power definitions - no calculation required to get those numbers. It is more accurate than Brawl Index because not only does Brawl not actually do the same amount of damage for each AT, it isn't even proportionally accurate between the primary and secondary sets on the same AT. (For instance, Blasters at level 50 have a melee damage modifier of -55.610 and a ranged modifier of -62.562.)
For example.
Brawl has a damage scale of 0.360000. This is true
regardless of the entity using the power. Tankers, Masterminds, Contaminated Brawlers... Brawl's damage scale is always 0.360000.
But how much damage would my Tanker actually do to a target (not accounting for resistances) if he hit it with Brawl? Well, for that value, we multiply by the
Melee Damage attribute modifier for Tankers at my level.
Level 1: 0.360000 * -9.600 = -3.456
Level 25: 0.360000 * -27.468 = -9.88848
Level 50: 0.360000 * -44.488 = -16.01568
Compared to the Melee Damage attributes for Blasters:
Level 1: 0.360000 * -10.000 = -3.6
Level 25: 0.360000 * -34.334 = -12.36024
Level 50: 0.360000 * -55.610 = -20.0196
So, what would our Brawl Index for those Tanker values be if we say that the Blaster's Brawl damage is our baseline?
Level 1: 0.9600
Level 25: 0.8000
Level 50: 0.8000
So, even Brawl Index isn't constant from level to level.
Further, when trying to compare the effectiveness of different powers Brawl Index is even less useful.
Comparing Foot Stomp to Blackstar (@ level 50, Blaster baseline):
Defender Blackstar: (4.875000 * -30.586)/-20.0196 = -149.10675 / -20.0196 = 7.4480
Corruptor Blackstar: (4.875000 * -41.708)/-20.0196 = -203.3265 / -20.0196 = 10.1563
Tanker Foot Stomp: (1.420000 * -44.488)/-20.0196 = -63.17296 / -20.0196 = 3.1555
Brute Foot Stomp: (1.420000 * -41.708)/-20.0196 = -59.22536 / -20.0196 = 2.9583
Notice that the Brawl Index value for Foot Stomp and Blackstar change depending on which AT you're looking at. So, the answer you get will depend entirely on which ATs you're looking at.
If, however, you're only looking at the damage scale of the powers, Foot Stomp is 1.42 regardless of AT and Blackstar is 4.875 regardless of AT. It's much easier to compare the powers that way.
And, let's imagine for a moment, that we want to see how much damage a level 50 Defender could do with if we proliferate Foot Stomp into a new Defender Ancillary Pool. Using Brawl Index, there's just no real basis for comparison - especially since the BI would vary depending on ATs. But if we use the damage scale and AT modifier:
Defender Foot Stomp: 1.420000 * -30.586 = -43.43212
We know exactly how effective the power would be.