RE: Wing tip engines + rudders.
Consider one electric motor getting knocked off, and still attached to the plane, and still running.
Euuuuuuuuuuuuuuuu!
I have been playing with seperate ESCs on a twin, to handle the rare occasion when one motor quits,
both as a pusher and a push-pull...
With this Gentle Lady, the plane is controllable at less than 40% power on one motor.. it will turn into the running motor.
More than that amount of power, it can't do that.
With a wingtip motor running.... I think "Frisbee" is an apt description.