The nice thing about Sondheim is that he was always crediting his collaborators and correcting them when people would give him credit for things that he didn’t feel he should take credit for. It’s a bit of a contrast to Andrew Lloyd Webber who seems to slap his name above the title of everything despite not directing or writing actual words for his shows.
On the case of orchestrations I actually think I recall he would thank them in every Tony speech for Best Score win too.
Give me claws and a hunch, just away from this bunch.