Just because there is some funding for non-statemented children, doesn't mean you don't need a Statement to access funding. What Leeds says is that if a child meets FFI criteria at level 2 then they will be allocated specific funding for them, separate to the general budget allocation.
If a child only meets the criteria for Level 1 in any band (ie. Band D - Physical) then they have to rely on the school allocating resources to them out of the devolved budget.
As you can see, all your DS gets 'entitled to' by meeting level 1 criteria is an 'individualised programme' - that could be 'roll a piece of plasticine in your hand twice a week';
availability of pieces of equipment and a variety of environment modifications - sounds great, but just because it is available doesn't mean he will be given it to use. If they have 10 sloping boards for writing, and 11 children who meet level 1 band D criteria, who decides who misses out?
support for special exam arrangements where necessary - who decides what is necessary? How do you know that they will follow through?
If your DS has significant SN, the only way you can be sure of his needs being met is to request a statutory assessment and obtain a Statement of SEN, whereby everything contained in it HAS to be done.