The Netflix deal is a cost plus deal I suspect as that is the way they do them.
The Sussex spend 6.5m on costs for a project and they get 10m from Netflix (Cost +) and they do 10 of these projects - that’s 100m
The Sussex are left with 35m after their own costs of 65m
But from that 35m they have to pay Netflix to advertise and put their program on their streaming service so that will eat into their 35m especially if they are doing one off documentaries rather than series.
what is also important is that Netflix owns the distribution rights so they make any money selling to other services so no syndication revenues down the road.
its a lot less lucrative than 100m