Yes, that’s what I thought, too.
We’ve been beating the physics of flywheels to death on this thread:
But, really, we’ve only scratched the surface. There’s plenty left to discuss, I think, especially when it concerns the variability of the ball squishiness, mass, etc.
If by speed you mean rotational speed of the wheels, then the short answer is: yes. But, of course, there is a minimum tangential velocity that must be maintained in order to provide the balls with enough initial velocity to make it to the target. More wheels provide more kinetic energy, which means that the wheels don’t slow down as much when the ball is accelerated by the wheels.
The single wheel launcher must spin faster not only because of geometric reasons (see the diagram) but also for kinetic energy reasons, otherwise it will slow down too much to launch the ball at its intended target. In the single wheel launcher, part of the kinetic energy is sucked up in getting the ball to spin (which might help it in other ways, however).