Clustered Index Maintenance vs. Nonclustered Index Maintenance
Embarrassingly, I never knew of columnstore indexes. This table is primarily used for analytics; thus I used a clustered columnstore index with a primary key defined on the char(2) and int fields as per the suggestion from David Browne - Microsoft in the comments.

Since the question was about clustered index maintenance compared to nonclustered index maintenance, I'll "answer" that part to the best of my ability. From what I've read, it takes more resources when a clustered index has a page split than a page split on a smaller nonclustered index (with the same key). This is because the page contains far more data in the clustered index. Consequently, had I not used a columnstore clustered index, I would have used (and tested) an IDENTITY column for the clustered index. Having said that, the video 
sp_BlitzErik provided in the comments is very informative—and easily digestible for plebs like me—and highlights how there is a lot of outdated recommendations "out there" based on older implementations of SQL Server; thus concerns about external fragmentation can be exaggerated.