I have worked with special ed kids on several occasions, but when I came to this question I thought it sounded like a final essay exam for a test.
Maybe you are a teacher... or maybe you are a student taking a final exam.
By using the word "orchestrating" I get the vision of someone directing various elements and instruments to adhere to a particular view of of a particular written composition with all of the specific notes played in a certain way at a certain time.
I have always thought that 'orchestrating' play was a bit oxymoronic.
With special needs children, you need to be more of an innovative jazz musician. It depends on what the needs are, as well as the interaction and the progression of the play time.
In my experience if the special players had a positive experience and interaction and no one got hurt or had a negative reaction (even if it was not what one expected or hoped for) the play is successful.
I think the term "orchestrating" doesn't fit well with special needs children. You can't necessarily expect an exact predictable outcome with special needs children.
It is not a symphony, but the music can be creative, exciting and positive.