Was just talking to my father in the UK about this. Are they allocated to different channels ? He checked the magazine guide (he's old - I didn't know they still made them) ! Maybe it was a newspaper. Anyway he said one of the 16.30 games is on BT, one on Sky and one on Eurosport.
I think some of the games are played a day later because of Thursday matches in the Europa.
Not sure why they're being played at 4.30