I think the schools have to give teachers the option to go part time or they leave.
I know job shares can work of course, but my experience in yr 1 is that it worked very poorly. The kids seemed really confused by it. Maybe it's easier when they're older or if they had the imagination to at least put a very strong LSA in there for the full week.
The teacher we have for three days is very able and I don't know about the 2 sayer.
I wonder how often a jobshare works really well in your experience as parent or teacher?
I mean, I wish them well but my experience has been it kind of sucks for the kids.