While I know where you're coming from, Eric (and Jim), I don't agree in this context. For a casual researcher to refer to Goodman's heap of companies as "Atlas or whatever," referring to Goodman's in-house distributor, is fine. The indicias are a mess, and from the perspective of the reader, don't make much difference.
However, each of those companies needed to file with the state of incorporation with relatively strict accounting of ownership. Also, writing and art contracts (or paychecks) would've been handled consistently by one arm and surely must have turned up by now. As an expert who must do exactly this sort of research routinely, it shows a lack of preparation or understanding. (It might be the "whatever" that's bothering me, because I would've accepted "Marvel or the group of companies that became Marvel" without hesitation.)
I mean, yes, it's possible to structure a bunch of companies so that there's no clear parent organization or ownership of anything, but unless you're doing some heavy-duty money laundering, that's a lot of time and money spent maintaining the facade to little useful effect.
More likely, as Jim suggested, they were just to keep everything divided below IRS limits and some asset protection in case he hit financial trouble; but that kind of organization is far more straightforward than naming the publisher.
Again, I'm just a software guy, with no legal training beyond the occasional pun-addled dinner with a lawyer friend and his (non-lawyer) wife. But I'm pretty sure that the paper trail would be open and easily-followed, to someone with the right resources...like an Intellectual Property lawyer who has dealings with Marvel talent, for example.