You need to correct the Spens genealogy.  The genealogy by Douglas is wrong.  Alexander married with Catherine Wood is not from Lathallan branch, but from Wormiston branch (see the works of David SELLAR on the subject printed in The Society for West Highland and Islands Historical Research's" n°xxii, Dec.83, p 21-26,

 or the works of

Harry D WATSON "Sir James SPENS of WORMISTON (1571-1632) a Scoto-Swedish genealogy" p 156 note 5. Harry D WATSON ajoute: Wood also confuses the Spenses of Lathallan with those of Wormiston; on page 452 he refers to JOHN SENS, bailie of Crail, in parenthesis as not of the direct line of Wormiston, omitting to mention that the said JOHN' genealogy is traced in full on page 146 under Spens of Lathallan. Cross-referencing establishes that he was the father of DAVID SPENS, rector of Flisk, who was the uncle of Sir JAMES SPENS'S great-grandfather! He (JOHN) was also the father of the WILLIAM SPENS who was erroneously mentioned in the Swedish genealogies as the progenitor of Sir JAME'S family in Svenska Adelns Attartaflor fran Ar 1857-1897 (Stockholm, 1897) p 433-5.

 The first Lathallan branch failed in Scotland with John de Spens, son of Robert.   I will send you the connection between Lathallan and Wormiston, Your ancestors are from the second Lathallan branch who is a cadet of the Wormiston branch

You can look at www.spens.info for the spens roots