Just go look at your Seattle org chart. I never said there was a "benefit," just that foreign national managers prefer that foreign national managers manage US offices and that is why they fear offices in areas that don't adhere to this globalist orthodoxy that is in the bay area and Seattle. That should be self evident.
There is no "Seattle org chart." A given office may have a lead, but only small percentage of people in the office will report to the lead. In some cases the lead isn't even a manager.
Personally, across four teams and six managers, only one has been a non-citizen and he was a permanent resident from an anglosphere country. Looking around, pick a random manager and you'll probably find a white guy from the US.