I saw the whitefronts where you had them this morning, in the stubble field just before Morfa Mawr farm. I only counted 15 but there are dips in the field as I could only see the heads of three of them.
They have been seen regularly there for a week now.
I agree that there may be two flocks, as they have also been seen twice in the fields by the Clettwr, 12-15 last Sunday and nine on Tuesday. It seems unlikely to me that they would commute between the two sites.
Perhaps both sites should be checked at the same time!