 McDonald believed that this " Mac Somhairle " referred to Donnchadh mac Dubhghaill , while Sellar thought that the clear favourite for this " Mac Somhairle " should be Domhnall 's older brother Ruaidhri . Alex Woolf more recently offered an extended case for the latter view , arguing on a number of grounds that Ruaidhri is by far the best candidate . 
