coincidentally, I was looking up the word sawney only this morning.
My father used the word of a person to mean rather moronic.
to my surprise it is a diminutive of Alexander and applies to Scots, not morons.
I think Sawney is a dismissive term for anyone in the gaeltacht (though strictly speakers would employ Lallans or Anglo-Irish rather than Erse).
"Sandy" would be the normal diminutive of "Alexander".
[Curiously, one of the earliest Scottish poems begins, "Whan that Alexander our king was deid ..." and goes on to lament the effects of sub-prime mortgage event on the economy of Scotland when Sandy rode his horse off the edge of a cliff in a fog.
Makes you profoundly to wonder, but.
Whirligig of time, and that ...
Robin (for the Black Gang)