Aye-aye-aye! This is a major relational database modeling case!
Your response is not what I wanted to hear, but it is defintely what I need. OK, that's definitely overkill for my purposes.
Since my main two purposes are 1) listing all authors in very particular orders; and 2) having built-in features for grouping publications by author, I will end up using both a custom field and a custom taxonomy:
* Custom field "Author list": single-line field in format "Lastname1, Firstname1, Firstname2 Lastname2, Firstname3 Lastname3"
* Custom taxonomy (non-hierarchical) "Publication author": format "Firstname Lastname"
Whenever I need to display the author list in my desired format and whenever I want to sort publications by author, I'll use the "Author list" custom field; whenever I want to list all publications by a particular author, I'll use the "Publication author" custom taxonomy.
Thanks for your help in clarifying my possibilities!