love to chime in but i've only read 3 or 4 issues of runaways. 😬 on top of that, the extent of ambrose's powers was really never shown, nor is it possible to speculate how it might fair against magic. drummer would likely be pretty useless--his technopathy doesn't occur mid-battle, he tends to need more time and he is strictly human. frost is quite the beast and jakita, while not as strong as molly, has it all over her in skill and speed (i'd think).
planetary are no pushovers, but again, without more knowledge of the runways and their powers, i can't give a real opinion.