William Soulis became Butler of Scotland in 1318, after the death of his remaining younger brother John II, who died alongside King Edward Bruce of Ireland. As this was a hereditary position, was John II Butler of Scotland when he died?

To have 360 squires following his banner, there must have been something very special about William.

I was given this information concerning the three Soules brothers today:
Sir William de Soules b: ABT 1239 d: BEF NOV 1293
Sir Thomas de Soules b: ABT 1244 d: BEF 1304
Sir John de Soules b: ABT 1247 d: BEF 01 APR 1311 married Margaret daughter of Merleswain of Ardross b: ABT 1245 d: AFT 1311 and they had a daughter Muriel de Soules b: ABT 1280 d: FEB 1317/18


Sir John de Soules, Guardian of Scotland.
i. William de Soules or Soulis, Butler of Scotland §D.
ii. Muriel de Soules (d 1318)

I take it that one of the three brothers had a son: John, who died in Ireland with Edward Bruce in 1318, the same year as Murial died and William became Butler.