But......
A quick look on the 'net tells me that the Gaelic name for the site we know as Callanish is:
na Fir Bhreign....or Fir Bhreig.....or Na Fir Bhreige.
Trying to Gaelicise a name in Scotland which is derived from Norse seems, well, as I've said, silly. Should all placenames in Scotland derived from Norse be Gaelicised and everyone use the new Gaelic name?
As for the satellite sites which have been given numbers, they do have Gaelic names. Most of us don't speak Gaelic and it's simpler for us to use the numbers.
All over the world people with different languages have different names for the same places. Should the French stop calling London 'Londres'?. Should we stop saying Vienna and call it Wien?