El Rocio isn't a million miles away from the Algarve, where common chiffchaffs are superabundant in winter, especially in the sort of Typha / reedbed habitat shown here, so I'm guessing things are similar there. Numbers seem a lot lower now as they're clearing off north, but there's still a few about. Iberian CC records are just starting to trickle into the local eBird reports. I'd agree with
@Butty these all look OK for common chiffchaff.
Also agree that no. 8 looks very like a sedge warbler; these on the other hand seem to be very much a passage migrant - I was hoping to see / hear one today in fact that had been reported at Aldeia Nova, but there was no sign.