> Side note: it’s important that no two proposers ever use the same sequence number, and that they are sortable, so that they truly reference only one proposal, and precedence between proposals can be decided using a simple comparison.

They are moving the core problem into a different domain. Worst explanation of PAXOS ever... nice animations though.

Edit: 'Worst explanation' is just an exaggeration, obv. It is nice, but doesn't explain really important issues.