Graybeard
The question is not one of relative complexity of a/c. Pitot failure (even all three "combinations"), is serious, but what is the reaction of the a/c? If in automated flight, what is the prescribed sequence of corrections or accomodations? Does the a/c hesitate, then initiate another 'regime'? Or does it give up, "parameters exceeded" and quickly revert the a/c to hobbled control inputs after automatically disengaging equipment that the two pilots have quite understandably grown to grant their immediate trust? Three separate computers? Excellent!! Some trained for reversion sequence with immediate and automatic displays?? NO??
Why is the Rudder attached so firmly to the VS? A Rudder is a trimming device. Without a Rudder? Quite flyable. No VS?? You are going down.