these are transactions with extremely high value and often extremely urgent and not possible to merge together - e.g. the both liquidate the same unhealthy loan position (could be worth ~$10m+)
the whole point is it's not remotely easy to just "reconcile separately" when you have two mutually exclusive financial operations - these are not code changes made by mutually cooperating developers happy to change their code to resolve merge conflicts, they are actively fighting against each other
edit: this also point out how having a centralized entity decide the ordering of transactions is a horrible idea - sequencing is worth enormous amounts of money and you could not be trusted to resolve transactions in a way that is sometimes against your interests but in the interest of other participants in the network
the whole point is it's not remotely easy to just "reconcile separately" when you have two mutually exclusive financial operations - these are not code changes made by mutually cooperating developers happy to change their code to resolve merge conflicts, they are actively fighting against each other
edit: this also point out how having a centralized entity decide the ordering of transactions is a horrible idea - sequencing is worth enormous amounts of money and you could not be trusted to resolve transactions in a way that is sometimes against your interests but in the interest of other participants in the network