"and as luck would have it are in the Sciennes PS catchment"
Similar.
We were in the JGHS before kids - but probably didn't know.
Then moved slightly and was in a different primary catchment which happened to be Bruntsfield which then fed into JGHS - even though almost next to Boroughmuir.
So (almost) chance where they went. First consideration was 'live close to centre of town'.
In Edinburgh 'inner city' means something very different to most places!
Being near to a very good state school was a bonus. League table good, but a whole more to it than that. A lot of Edinburgh parents send their kids to local primary then private.
Obviously there are individual reasons, but whether they always get a better education is debatable (and largely unknowable).
Chris Hoy did well in cycle sport because of basic talent AND putting in the effort - plus having the family background where he was encouraged and driven to BMX races. I think that was just his father when he was in Scotia BMX.
Watson's might have preferred him to stick to rowing.
And yes, he IS a genuinely nice person.