I think the auxiliary pitot/static is enough. The belt and braces is employed in this system. It has failed yes, but where do you stop mounting probes.
If we are going down this road they might aswel add another engine somewhere in case the primary fails.
If not, bit of light hearted food for thought. How to spoof the signal from another source using another system.
Pack ram air inlet sensor for pitot and..... Cabin air controller for static
I will have think and look forward to ppls suggestions