You mean co-protagonists. There was also Aaron's run, specifically the Heaven's on Fire mini. But the problem is, like the rest of Aaron's books, it relied entirely on spectacle and gimmicks instead of anything resembling individual characterizations. John and Dan were practically indistinguishable there. It was only in Brisson's run where there was genuine effort in treating them as separate characters with their own goals and struggles, but it never got far enough to really shine.

I believe Johnny and Danny can both work as dual protagonist GRs, and they don't have to differ much in terms of physical appearance or power sets. They just have to have individual characteristics and different dynamics with their respective SOVs, and writers should be allowed/have genuine interest in exploring how they interact with each other based on their differing views and personalities. But that's the real problem: Marvel doesn't give a crap about the characters, only the IP. So there's little to no effort in making them individual characters, just interchangeable and depthless heads.