I'll just flag that a Canadian bank who had decided to extend several of their existing "global" models to their US subsidiary based on similar logic, and while the logic makes sense broadly, they ran into significant issues with their US subsidiary’s regulator about the way they did it
I would primarily attribute the root causes of those issues to:
Operating model for how those decisions were taken and where they were reviewed and challenged – the Group development and validation teams led the substantive assessment of “fit-for-use”, and while there were some US stakeholders involved, the ones most involved were not very senior in stature, and often deferred to the expertise of Group. But those US stakeholders then couldn’t / didn’t do a good job of credibly defending those decisions to their regulators, leading the regulators to question if US senior management had been sufficiently involved in determining that these models were appropriate for the US portfolio
The documentation they produced justifying and validating the use of these models in the US was a narrow “fit for use assessment”, which taken as a standalone artifact fell far short of the comprehensive model documentation and validation expectations of SR 11-7. This led regulators to question the “effective challenge” provided by US model risk management and more broadly by US senior management