Fingers crossed then :) It's good that the rest of the floor framing is elevated and ventilated. I suppose you are trying to minimise the lost space but it is also very sensible to have sufficient access to clear leaves and other detritus from between the fence and shed. Again, this accumulation can lead to corrosion/rot of the shed.
I spent a few weekends at the start of the year jacking up my shed with car jacks because the floor had rotted away. It was built directly on a concrete slab.
Some pavers (maybe 4 or 5, corners and centre), a few plastic packers or wood and some offcuts of dampproof course would allow you to support the joists in addition to those posts. Simple to do now and a total pain in 5 years time.