I have been delighted to find in The Oxford Guide to Heraldry on p. 123 this
Since the sixteenth century, quartering in England has signified representation in blood, and if it is subsequently established that a pedigree is incorrect then the right to quarter is lost and and does not continue on the basis of an earlier confirmation.Unfortunately my grandfather's scheme of quarterings contained several errors that lead to the exclusion of quarterings from the Kingmakers. Several of them were akin to the inclusion of earldom arms mentioned previously, in that the arms of territory settled on a wife were treated as the arms of an heiress, even if she had brothers. So, such territorial arms must be excluded. The curious thing is that these quarterings were originally signed off by Clarenceux in c.1926 and then the pedigree documentation to support the artwaork was produced by a herald in 1996. The set of arms to be excluded is:
The Mandeville exclusion does not apply to the Kingmaker as William Mandeville is not in the Kingmaker's ancestry.