Specifically, it must be seated where the principal management of the business occurs.

So if the executives and board meetings and books and records are strategically located in one country and most of the business operations are in a second, it's valid and probably even required for the business to have its tax residence in the first country rather than the second.

It may very well have a permanent establishment and therefore some tax obligations in the second country, but that's different from the second country being the primary tax residence.