In the beginning, TfGM were very dough eyed with the Hybrids becuase of the green credentials od such a system (better than full diesel) but by the time they realised that old hybrids rarely work as they should and would cost an absolute fortune to refurb the mechanicals, they had already done a hat full of the Oxford ones and painted most of the ex FirstBus ones...
I have asked if they plan to send the ex Vantage ones away for converison to electric as they are considerably younger but no one knows..!