It comes from Alpha T-400 ...
The T-400 is an homage to the original Rubberset. That was always clear and as far as I understand the whole intention from the beginning. Based on that, Alpha took the ridges design element as inspiration and created something of their own with it. With the Rubberset, the ferrule has a large diameter and a mostly narrow handle part. The Outlaw is quite the opposite with its pear-shaped design, and the ridges are broader. It feels very different (and in my opinion, much more comfortable) in the hand.
The other aspect here is: The Rubberset is a classic and discontinued item. The Outlaw is a modern and currently available brush. It's one thing to revive something from the past, and I applaud people for doing so and keeping designs accessible. It's another to copy something from the present and leapfrog the whole r&d process while entering into direct competition with those who did the work.
(Alpha Outlaw, Alpha El Gordo, Alpha T-400, T-400 ferrule)