Argyll was the home of many McIntyres too which is where my gr gr grandfather was born. That said, something you may or may not know, it was quite common for female children to take on a mothers maiden name as part of their name. As an example, I have a Janet Taylor McIntyre. Janet Taylor was my gr gr grandmother so the name carries down. Her Husband John, was born in Inverary,Argyllshire in 1828. His parents were James and Catherine(Nee Currie). As to the spelling Mac or Mc-again a choice. my dads brothers spell it Mc, but due to the Canadian military, dad was given no choice on the spelling. Mac. I do know there are connections, but is a road I have not explored yet. My gr grandfather is buried in Auchencairn. sned me a PM if you like with an email, and I can send you more info if you want.
Marc