If you pick the Arts background you do get the chance of recruiting another one of them. It happens around the end of Build 0.5, if memory serves me. You can pick a decoration for the lounge, and which one you pick determines which of the other two available guests you recruit.
That's the only way to recruit a second one from that set of guests, though. It's the big advantage to the Arts background, much like the Leader background may allow you to recruit both Pedro and Nikos.
However, you will be able to recruit other characters later by doing side-quests. For example, starting with Chapter 19 finishing all hangouts with specific characters may unlock R&D projects that bring in unique characters, and there's at least one guy in our plans who will require a number of conditions to be recruitable :p
We know people want to get everyone together, but... You know, you can't help everyone. Even if the hotel has infinite resources, time is ever so precious and scarce...