The deciding factor wouldn't have been the people themselves, it would have been the type of magic they used.
The Charmed ones used spell magic, which is ok. But they'd have to be in a running battle.
Willow used thought and sometimes hand magic.
Can you imagine them in a stand up fight in the attic?
Piper could be transported to the Isle of Man, Paige would appear/ disappear every time she got scared, and Phoebe would run to the kitchen every now and then to get some herb or other. Mind you if Willow watched her bloody stupid running style, she would probably have collapsed in hysterics. And that is the only way she would lose.