From the user perspective, they really only know about "their site" and not all of the other sites that are out there. I know I'm being vague (confidentiality reasons), but think of it as SaaS where your company can buy access to content and testing material that is only available to your employees. Another company may get access to the same stuff, but it is available only through a URL that's customized to them.
My basic thinking is that if the content is not unique, it's password protected and the user's experience is relatively solid (aka they don't stumble around the URL structure), then possibly the only way a consolidated URL structure could add value to search would be to have some sort of content strategy to increase the publicly available content on all of these sites. And even then we wouldn't really have an inbound linking strategy to these pages as they are really client/employee specific...so we'd be back to producing content for the corporate presence rather than these individual sites. Okay, now I'm rambling but I'd love a general nod if at least my logic is sound. I'd happily take any challenges to my thought process as well! Thanks!
