I'm not trying to contradict Solomon's reply, but I lead our partner-centric solution architect team and we do send a good portion of our time in the same sort of engagements the Office of the CTO do, just in the context of three party (Google+partner+customer) opportunities. It's fun and I'm hiring (MTV, Bangalore and Paris).
There's certainly some overlap, though the Solutions Architects (SAs) are more explicitly focused on publishing solutions (cloud.google.com/solutions).
My team is composed of a mix of Google engineers that can (kind of) talk to people, and recovering CXO types from various industries (Finance, Healthcare, etc.). Each of us try to only work deeply with 1-3 customers at once, while SAs are usually focused on more broadly applicable solutions.
We all weave in and out depending on personal relationships with customers and individual skill sets, but we're all behind trying to make our customers successful regardless of role or title.