I feel like that idea is erroneously mixing concepts. You want quorum in safety critical contexts, generally to guard against hardware failure. I think using independent implementations in such a scenario is uncommon and to date largely a stop gap to save money by replacing formal verification.

For security formal verification is really what you need. Both of the software and also eventually the hardware, since typically formal verification of software won't hold up against something like rowhammer. (Although TBF I'm not sure what sort of formal verification would have caught rowhammer.)