If they are that untrustworthy I’m a trifle unclear on how Walmart intends to make this work.
If you want multiple mutually untrustworthy parties to be able to pass around abstractions in such a way that double spending/replay attacks aren’t generally viable that’s a thing you can do. (And an interesting one; preventing double-spending of things that copy with the pristine perfection of digital data is neat.)
The half of these omg-blockchain-logistics arrangements I’ve yet to hear anyone explain is how you deal with the fact that preventing tampering is at best incomplete (at worst actively unhelpful if it lulls people into a false sense of security) if people putting lies (or sincere beliefs that have been tampered with downstream) into the system is a risk.
If people lying to you isn’t an issue you only need to make sure that your DBA isn’t in the pay of a ruthless lettuce cartel and your problem is pretty much solved. The only other vaguely novel tool you might use is GUIDs, so that you can serialize the produce without coordinating blocks of values among your vendors ahead of time.
If people lying to you is an issue, then enshrining their deceptions in future immutability is of limited benefit; especially in a case like this where there is a fairly clear authoritative party that trusts itself and whose suppliers are obliged to cooperate with.
