The text and photos are from RCM. Yes, the 2nd photo shows the crank balancing only the rod and wrist pin. That is why he ground all that material off the crank around the crank pin, to lighten the side of the crank opposite the counterbalance. By making the crank pin side lighter, you enable the counterbalance to balance out more of the piston weight.

Maybe he should have taken a shot after with the piston, rod, and pin to see how much he got it to balance.

And as far as the shape of the crank throwing mixture up into the ports..some RI engines have totally round disks for counter balances and they run fine.