Sorry, I don't have the book. What are the 5 issues listed for Ae2 and which one is Saewine missing? I'm guessing it is Helmet following the sacking of Wilton in 1003 and the relocation of the mint to Salisbury?
It surely has to be three generations involved. Ae2 ruling for 37 years is compact enough to be a single person, but with a break until EdC type 7, you have a gap of 40 years, so grandson seems more likely (if relevant).
Locations in the interim (Cnut to H'cnut) with a Saewine listed are Bristol, Exeter, Leicester, London, Lydford, Oxford, Shaftesbury, Totnes and Winchester, so one moneyer located in the west and travelling around. with only Leicester and London as outliers suggesting a second person. The two EdC issues involved imply a considerable increase in mint output if the number of moneyers was increased from 2 or 3 to 6.
From the table, EdC hammer cross to W1 first issue, you are looking at a gap of only 4 or 5 years before returning - assuming we are talking about the same person. For the period from Sov Eagles to William 2 type 3 is another 35 years. It must be the grandson if descended from the first.
North only lists 6 mints with Saewine during EdC. Wilton, Winchester, Bristol, Exeter, Leicester and Northampton. This almost certainly refers to 2 moneyers, with one located in Wessex and the second on the Mercian border. The locations listed in North with S(a)ewine during Williams 1 & 2 are Exeter, Gloucester, Leicester, Northampton, Wilton and Worcester. The continual employment of Saewine at Wilton from William I type 1 to William 2 type 3 might imply a third person of that name doing the rounds. The only missing one is Sword type which is a rare issue in any case.
Although North is dated as a reference, the list is complete enough to give a reasonable view of who worked where and when.