In conversation, I just said:
Здесь не обошлось без помощи то ли специалистов, таких, как он, то ли еще кого-то.
Аs for who "не обошлось", I was referring to the entire medical personnel in a hospital. So in a sense, I had particular individuals, "они", in mind, but at the same time it is arguably not as distinct and specific as, for instance, "он/она".
What I had in mind was something like: "Here at this hospital, they (I was vaguely referring to the entire medical personnel) couldn't have managed/got by without some outside help from an expert in the field". I happened to use the impersonal construction without the subject "они (обошлись)".
I'm wondering if I should have placed the subject "они" with the verb "обойтись" instead of going for an impersonal construction.