Providing tools to make "mundane" encounters interesting is tricky. It'd be easy to expand the tables, but would that really help a GM running a game? What tools are immediately useful, and what could be folded into other sections of the book?
Basically, if I'm going to take up 3 pages on Mercenaries, are the ideas present worth the page space?
I think so. Full-page statblocks aren't usually my thing, but I'd like to provide useful tools that most other Monster Manuals ignore or stick in an appendix, without filling a page with excruciating and difficult to parse details.