Mr Thant wrote:

4 peak, 3 off-peak. I think they have 6 of them in total (plus 2 on
loan to FGW). End-to-end journey is 35 minutes, so you need 5 or 6 for
the planned 15 minute frequency. Having 9 would cover an hourly run to
Clapham Junction, though I've no idea if that's the intention.

I thought that the two that have passed to fGW were off-lease with TfL and
are now part of the "official" fGW fleet?