If I understand you right, you are speaking of radial spoked wheels. The basic rule of spoked wheels is, more spoke crossings adds axial and torsional (side to side and pedal/motor drive) strength as well as a softer ride. Less crossing and you have a rigid radial (up and down) strength i.e. harder ride and less torsional and axial strength. So the balance is 3 cross laced wheels.
On radial spoked wheels all the spokes go straight out from the hub allowing the spokes to pivot (the hub can move independent of the rim more easilly). So when you accelerate, all the spokes are being pulled on from the hub; when you brake they are being pulled on from either end depending on the brakes being used. On a cross spoked wheel 1/2 of the spokes are being pushed and 1/2 pulled in either operation. In addition the spokes are angled toward/away from the forces so that the force is directed down/up the length of the spoke rather than at the nipple and butt (the ends).
I have seen people use them on m/b's. It's possible that the sheer # of spokes adds enough strength, I don't know but radial spoked wheels are designed to look cool not for performance.