Denormalized data makes a mess of the application code: you end up having to do all kinds of funny work to make sure that their affiliation is added to the right spot (affiliation_1? affiliation_2?), and if you remove it, then you end up backtracking and rectifying how your assignments work. And that's assuming that you don't accidentally run into a case where someone has 4 affiliations.
This whole concept is physically painful for me to even consider.
Before you start denormalizing your database, you should talk to a DBA and see what solutions they might have. And step #2 would be to be smarter about pulling back data than slurping back the entire database via your ORM.
Between those two options, you should be able to get the DB performance you're looking for without hemorrhaging functionality and extensibility.