The "loons and quines" thing was completely new to me when my family moved here in the early 80s. I was brought up to speak "proper" English, although I was used to hearing Scots words being used in everyday speech. My grandparents sent my mum to elocution lessons - presumably so she'd be able to find employment without the hindrance of a regional accent (as was the done thing then) - but I was never really exposed to the Scots language until we settled here.Indeed ! I gather, the north-east of Scotland; where they do things to the language to the point that it approaches becoming an altogether different one. In a long-ago stay at a B & B in another part of Scotland, where the wife of the couple running it was from the north-east: the conversation turned to accents and dialects... we learned that where the lady came from: any male person of whatever age or condition, is addressed as "loon" -- doesn't imply mental impairment, it's just an approx. equivalent of "lad"; correspondingly, any female person, is "quine". The equivalent greeting to "hello, how are you doing?" is "Fit like, loon / quine?". Not meaning -- my initial figuring-out -- "are you sort-of feeling fit?"; but, "what [is life] like [for you at present], Sir / Madam?"
At the risk of coming across as a condescending received-English-speaking Englishperson: I really like the above -- find it marvellously weird.
The local language leans more towards the north-east, but as we're near the western boundary of what was the "Grampian Region", there is a bit of a Highland influence as well. I don't think there's anything condescending about your post - I find language a fascinating subject, and its variations should be celebrated.
To get back on topic - Tesco was never a big player in this part of the world. They had a large store in Aberdeen and one in Dundee, but their expansion in this neck of the woods was down to them acquiring Wm Low (Willie Low's). Marks and Spencer were also a rarity, and only known to be in the "Big Toons", but we've got a food hall in Elgin, and they're still known simply as "Markie's"