Sorting a table view alphabetically of a set of nodes on a taxonomy field that shares the same vocabulary as another field

I am using Drupal 7 with views, and have created table views for 4 different data sets on my website (Architecture, Theater, Education, Philosophy). For each table view, I need to make the columns alphabetically sortable. I have managed to sort on text fields and date fields just fine, and have found a work-around on making the sort work on fields that are taxonomy terms (as long as the vocabulary used is unique -- i.e. the field in the view is the only one using that particular taxonomy vocabulary on the given nodes/data type set). Unfortunately, bcs of the data that I am working with, in particular for my Architecture data set, the architecture nodes have several fields that share a common taxonomy vocabulary. For example I have fields: "primary architect", "secondary architect", "additional architects", and all of these share the same taxonomy vocabulary called 'agent' (but not the same term value). When I try to sort on these types of fields in the table view I can't get it to work. I have tried the work around with adding relationships (Content: taxonomy term on node) and sort criteria (Taxonomy term: name) that worked for fields that have a unique taxonomy vocabulary but I got duplicates. I tried filtering these by creating new template files and removing the redundant pairs but that didn't seem to work. And now I'm beginning to think that I'll have to write a new module to append views in order to make this work either. Could you point me to where the SQL query is that creates the table row arrays is and/or where I'd need to modify the query to take into account this scenario. Any help is GREATLY appreciated!!!!!
Thank you in advance!