The main problem here is flight. If Iron Man stays way high up- above jumping range, then they don't have a good way to attack him.
If they can bring their foes down to their altitude, however, they can win.
You do realize female Cheetah is faster than him, right?
She got a boost training with Zoom, after which she did stuff like tangle with Wally West, pretty much taking him apart until he used his momentum-draining power.