"Ron, How hard is it for a penguin to maintain a bombproof roll switching between a feathered Euro paddle and a Greenland paddle (and a wing roll for that matter)? Must take a lot of pool time. "

If you paddle and think like a penguin it is quite easy to be flexible in your choice of propulsion and rolling gear. Sometimes you don't even need a paddle. We should all strive to paddle like a penguin. Maybe start a new kayaking movement? ;-)