Its definitely true.
We are butting against the limitation with having too many Melee ATs without enough differences again.
Realisticaly Brute Armor set modifiers should probably be bumped up. So they actually have more mitigation than scrappers, not just HP and not just at the cap. Since basically they are now seen as a "TANKING" AT that lives a bit down the DPS slide from Tankers.
That's normal in a lot of MMOs.
The Brute was designed not to live on Teams with Scrappers and Tankers. In that other world, they were and would have remained fine.
If a Brute were more survivable it would reduce this disparity that you point out as well, without having to Nerf Tankers, or let Brutes step on Scrappers' toes DPS wise.