Some interesting stories about arms and people who supported The Bruce
Agnew was Lord of Larne in Antrim and fought alongside Edward Bruce brother of King Robert a Norman/Scots. They besieged Carrickfergus Castle with Norman/English forces inside. The English/Normans, even ate some Scots who had come to parley. My Peter (I think) Dobbyn ancestor was inside the Castle and I expect thoroughly enjoyed eating my likely also ancestors outside. I think Edward then thoroughly defeated went away to Rathlin Island and in a gloomy fit in a cavewatching a spider build its web many times famously said "Try try and try again"
Though that story is different form the standard version, though I think it makes sense
Incidentally Rathlin Island I read was where King Robert's wife hailed.
"Bruce, in a letter to the Irish chiefs, refering to the Irish and Scots collectively as "nostra nacio" (our nation):
“Whereas we and you and our people and your people, free since ancient times, share the same national ancestry and are urged to come together more eagerly and joyfully in friendship by a common language and by common custom, we have sent you our beloved kinsman, the bearers of this letter, to negotiate with you in our name about permanently strengthening and maintaining inviolate the special friendship between us and you, so that with God’s will our nation (nostra nacio) may be able to recover her ancient liberty.”
In other places, Bruce calls Scotland "Scotia Minora" and Ireland "Scotia Maiora." In Ulster, they shared his views. The Annals of Ulster write, s.a. 1314 :
"Roibeat a Briuis, ri Alban, do thecht a n-Erinn maille re galloglachaibh imdhaibh i furtacht Edubaird, a brathar fein, do dhichur Gall a h-Erinn."
“Robert Bruce, king of Alba, came to Ireland along with many gallowglasses in aid of Edward, his brother, to expel the Foreigners from Ireland.”
Donal O'Neill, told Pope John XXII that he had supported the Bruces because “the Kings of Lesser Scotia all trace their blood to our Greater Scotia and retain to some degree our language and customs.”
The idea that the common language was English is just absurd. There's no good evidence Bruce even spoke the language, and given he was a Gaelic Mormaer of Gaelic and French origin, there's little reason to presume he did. Donal O'Neill probably didn't speak English either. "