I'm also of the belief that a good number of Normans that came with William were Z196* (my own surname included). This might also account for the high number in England vs Ireland for example.
What are the odds the higher frequency in England is due to Anglo-Saxons?
I'd say they're pretty low.. DF27/Z196 has been in the Isles for a very long time.. Probably arriving with the L21 horde. Infact, I wouldn't be too surprised if DF27 didn't represent the oldest strain of P312 in the Isles.
Of course many will regard that as blasphemy, because we all know that DF27 is completly and totally Iberian and only recently made its way from there.
We are glad that you are seeing the errors of your ways and we will not condemn you to heresy.
"The Iberian Inquisition Institute"