Let's try a common sense approach, which I seriously doubt will work.
The basic reason WalMart HAS a "gun policy" is to address this issue nationwide.
I seriously doubt each and every store manager/asst. manager/stock clerk was consulted. Once drafted, this policy was shared with the individual stores. It's pretty much WalMart "law."
Now, that said, what useful purpose would it serve if any nilly- willy local manager can override it? What's the purpose of HAVING a corporate policy in the first place?
I assure you, if a Walmart manager asks ME to leave in light of their policy, I'm going for the gold, see them in court.
Of course, there will be NO OCDO attorney available, I'll have to do the best I can, alone, which is par for the course.