Another place the MacLeod genealogy is relevant to the theory about Torlack is the heraldry. I've brought this up a number of times already without specifically mentioning the MacLeods, but I think it might be time for some greater detail.
There is very little doubt among Scottish experts that the emblem of the old Norse kings from this dynasty was the ship. The triskelion is much later.
For example, here are two illustrations of the seal of Harald I, who was a cousin of Torlack's supposed father Harald II:
http://www.isle-of-man.com/manxnotebook/manxsoc/msvol05/fp1.htm
http://www.isle-of-man.com/manxnotebook/manxsoc/msvol05/fp2.htm
The originals of this and other seals were lost in the fire in 1731 so these drawings are all that survive.
British historian William Camden wrote in 1606: "But yet the ancient arms of the kings of Man was a ship with the sail hoised, with this inscription, Rex Manniae et Insularum,- " The King of Man and of the Islands," as I have seen in the seals they used."
Isle of Man website: http://www.isle-of-man.com/manxnotebook/history/legs.htm
The same website says, " the earliest surviving representation of the three legs would appear to be a detail of the arms of the Kings of Man on the Priest's tomb (probably that of Edward IV's chaplain de Grimsby) in Beverley Minster Yorkshire. The earliest representation on the Island is on the 14th century Pillar Cross of Kirk Maughold which probably dates from time of Montagu possession (1333-1391)."
Willima Blundell in his History of the Isle of Man (1648-1656) says, "We may observe yt so long as the King of Man wrote himself Rex Manie et Insularum, they bare the ship ; but after the Scots had gotten into their possession both the Isle of Man and the Western Islands, we find no arms born by them than the 3 leggs only."
Blundell's History: http://www.isle-of-man.com/manxnotebook/manxsoc/msvol25/ch205.htm
Clarencieux King at Arms in his official examination of the arms of the Kingdom of Man (1735) complained that Camden had not given further details, but says he himself has seen the seal of Olaf Gudrodsson with an effigy on horseback on one side and a ship under sail on the other. As a result of his examination of the evidence, Clarencieux gave his permission for the duke of Atholl, the current ruler of Man, to use arms with a ship.
Opinion of Clarencieux King at Arms: http://www.isle-of-man.com/manxnotebook/manxsoc/msvol04/v1p117.htm
When I look at this material, I wonder why, if Torlack Skenck was a son of Harald II, he would use a different coat of arms than the rest of his family.