well with Dolphy, at least I assume that the gaggle of "last recordings" at the time was really just a diverse bunch of albums he was making, without an eye to the "end." His departure was so sudden. Ayler seemed to have premonitions of departure, and the Shandars are definitely a step up from the frustrating final Impulse dates.
I often feel like Ken McIntyre's inclusion on Unit Structures was a nod to Dolphy vis-a-vis Cecil. I assume that's why he was brought in, but am not 100% sure, and of course, McIntyre was a strong player and had his own voice (those UA and New Jazz LPs are tight).