Many users tend to create feature classes that are "thin" in terms of the number of fields but then load up the attributes via an established relationship class. The most common example would be a parcel layer with a unique identifier connecting to one or more tables via a relationship class.
The user should have the ability to use ArcMap's Find functionality to search the feature class attributes AND related tables simultaneously. I'd envision this could simply consist of a checkbox to "Search related tables" that a user could click prior to running a search. I think this would be a time saver since many ArcGIS users deal with related data tables quite frequently.