I think he took down Cable and X-Force, because he got them by surprise. They had no idea what they were up against. I don't think Adam could take them all down again, that easily. And it's evidenced in X-Force #29/30, when he's fighting Shatterstar in Murderworld. They're going at it, trading blows - even after Adam does "flash fry" Shatterstar, Shatterstar gets up and kicks Adam in the face, and says he's too stubborn to go down in a fight.
And you say, change his power because he can take people down. Technically, so can Cyclops. One wide blast of his Optic blast should take everyone down. Wolverine, he can keep fighting with a thousand ninjas stabbing him through every vital organ, but that's certainly not an issue, writing him. Hulk, completely impervious to pain, but he's had his own series. A writer - a good writer - knows how to make these heroes (and villains), despite their power sets interesting. Otherwise, Superman would have never been the success he is. Because, well, it's Superman. Do I even need to try and explain that?