Hello Redmist,
I agree with Daniel, your bird(s) looks good for a male
thunbergii by grey head with at least one of them showing a slightly darker (more blackish) mask behind eye (hard to write mask, as its not a contrasting patch) and lack of an supercilium. There are some white speckles and just the faintest stripe in the loral area in the second bird (if real, they must be two birds).
But I must admit, I wouldnt hesitate one second to note them as
thunbergii when seeing them during the right time in Germany.
This ssp is a regular migrant, so I got a picture in mind of a thunbergii and your bird is a good match (and a wrong one for ssp
flava)
.
But I understand your hesitation, as you observed them in the zone of contact between
flava and
thunbergii according to literature and the appearance of your bird(s) can well be explained by some introgression from another ssp.
So: is your bird within acceptable appearance for
thunbergii? As said above, I didnt thought much about this in the past, but this question is one for real experts.
I am not so sure about the whitish throat. Slight overexposure makes faint yellowish hues harder to see, but I think they are thre (leaving a faint whitish moustache? Or is this an artefact by enhancing contrast by the jpeg engine?). Regarding a possible ssp.
cinereocapilla, there is an excellent paper in German by Jörg and Thomas Langenberg:
OTUS Heft 1, S , November by Otus e.v. - Verein für Feldornithologie in Bayern. 11 Gefiedervariationen bei Aschkopf-Schafstelzen Motacilla cinereocapilla Jörg Langenberg 1) & Thomas Langenberg
docplayer.org
It comes with a transcript from the text, helping to cope with german language to foreign readers in times of translating programmes.