I'm with Roger here.
The appropriate title to me seems like "Principal Architect."
At least in my opinion, someone at the "Principal" level
is giving technical direction to more junior people as well
as performing some project management and scheduling responsibilities.
Of course, we also have a "Senior Principal Engineer" title here, whatever THAT is supposed to mean.
In reality, titles are extremely variable by company.
I've worked at one company where "Fellow" was the highest technical title, only bestowed on a dozen people out of 10,000+ employees.
And I've worked at another company where "Fellow" meant basically "college intern." I.e., the very lowest guy on the totem pole!