Some examples of what I mean off the top of my head> Tek Knight> has a brain tumour and it keeps making him want to fuck things
That's pretty much all there is to his character, besides the fact that he doesn't technically have superheroes. He's meant to be a rare example of a genuinely good hero but he just comes across as a little kid's attempt at making a "mature" parody of a Iron Man/Batman/whoever. You could easily rewrite him to be some kind of mentally ill superpowered nymphomaniac who kills hookers whenever he climaxes, similar to that scene from The Pro (also written by Ennis). He feels horrible about it but it's a clear example of how a relatively low-risk illness (nymphomania) suddenly becomes a massive danger to the public with the addition of superpower, adding to the setting. His guilt makes him a more interesting and nuanced character. Hughie could investigate this and reflect further on his own strained relationship with his girlfriend (especially when he finds out about her former sex life).
Instead, we get a pretty weak joke of a character who doesn't do much for the story itself.> Super Duper> a team of developmentally disabled adults who are stuck with superpowers
I was pretty excited for how he'd spin these characters. Maybe they'd be a major danger to the public just like I suggested earlier with an alternate version of Tek Knight, even though their illness would normally be relatively manageable. Maybe Ennis could dig deeper into how they're just another casualty, a byproduct of a major corporation that doesn't care about what it's doing along with a public health service that treats even superpowered disabled people like trash. There could have been some deeper attempt at social commentary than "they're innocent because they're developmentally disabled." Just felt like another example of a wasted opportunity with disposable characters.