Although, central to the point I'm making is how one defines "Scots-Irish". Many of the illustrious American families - especially in the South! - laying claim to this lineage are the product of intermarriage(s) between arguably the freedom loving cream of both 'races'.
Further, the distinction between them is largely cultural as they're essentially the same Celtic people. As example, the MacDonalds - of the ilk of the legendary "Lord of the Isles" and the de facto 2nd Scots family after the Stuarts* - at one point in their history controlled more territory in Ireland than in Scotland.
The "Scots-Irish" now resident in Northern Ireland are another matter entirely being mainly the descendants of Protestant zealots & opportunists who willingly occupied knowingly stolen lands to assist in England's imperialist machinations on the Emerald Isle.
A 'more English than the English' crypto-Nazi hate-monger like today's
Ian Paisely most certainly can't be mentioned in the same breath with the numerous heroic Scots & Irish volunteers who served along side Poland's famed Jan Sobieski when he crushed the hordes of militant Islam at the Gates of Vienna on 9/11 1683!
*
not withstanding claims to the contrary from Clan Campbell which entirely owes its prominence to 300+ years as England's principal traitorous Northern toadies.