On closer examination it became obvious that something was amiss in the genealogy of the 16th century family of Edmonstone of Duntreath. When time permitted, the Duntreath muniments for the period 1500-1600 were again read through but all appeared to be in order and each generation was, apparently, accounted for. The issue was finally resolved with two services in favour Sir James Edmonstone of Duntreath (died about 1618). The first was expede on 29 July 1614 and is in favour of Sir James as heir to his "avus" [grandfather] Archibald Edmonstone of Duntreath, in the lands of Cambuswallace. The second is dated 21 April 1615 and is also in favour of Sir James as heir to his father, William Edmonstone of Duntreath, in the lands of Easter Glenboig and the officer Coroner of the sheriffdom of Stirling. By virtue of those writs considered together as new evidence, the omission of the grandfather, Archibald Edmonstone, is confirmed.

The question of why Archibald Edmonstone has hitherto been overlooked becomes obvious by reason of the content of that same evidence. The service of Sir James to him confirms his death occurred in June 1544, which is the precise month and year in which the feud between the Edmonstones and James Stewart of Beith over the right to the office of keeper of Doune Castle erupted into open conflict and during which Archibald's brother James and his sons William, Archibald and James killed Stewart at Dunblane on Whitsunday of that year. In all probability the "missing" Archibald had succeeded his father by only a matter of months if not weeks before he too became a victim of that feud and with such a shortened tenure as laird, few items of evidence relating to him were ever being produced.

That paucity of evidence has understandably resulted in inconsistencies. Foremost is that William Edmonstone of Duntreath, Archibald's father, and Archibald's eldest son and successor, also William Edmonstone of Duntreath, have been conflated into one person, As a consequence evidence citing relationships to a "William Edmonstone of Duntreath" have been considered as they relate to that single person instead of, rightly, to the namesake grandfather and grandson. Archibald Edmonstone's inclusion as a laird of Duntreath reconciles the chronological issues surrounding the legitimation of James Edmonstone "natural son to the late Archibald Edmonstone of Duntreath" in 1553, when the only previous Laird of Duntreath of that forename had died by 1503 at the latest. It also has the effect of proving William Edmonstone of Duntreath, the grandfather died before June 1544 and was not twice married, but instead, his only wife was Agnes Stewart of Lennox with whom he is named in March 1518/19. It additionally proves that it was his grandson and heir, William Edmonstone of Duntreath, who married who Margaret Campbell of Lawers about 1550, not, as has previously been accepted, that William was husband to both and died in August 1577.