Venture, the thing that makes Brutes capable of reaching those levels is Invention Origin sets. They start out with Scrappper-level defenses and can cap at Tanker levels (although, their hit points aren’t the same). Brutes are fine (even with the slight damage cap reduction), this is just giving Tankers some long needed Parity.
That was a good catch on that taunt magnitude increase. Most people might not remember that from the original patch notes. If Brutes are constantly taking aggro, then my guess is that you’re running Willpower, which does have a weaker aggro aura. If so, add a Taunt IO(s) into that and cycle Taunt into your attack chain. Also, the 17-mob aggro cap can allow some aggro hemorrhaging, so be aware of that.