There was only 1 other TABLETOP Role-Playing Game I attested myself with, and that is RIFTS. I had a SOURCEBOOK that included a "Headhunter Academy" with an actual obstacle course to Role-Dice for.

The Mercenaries book came first, but I take that experience to the Dinosaur Swamp area. 

So far I, thanks to the Mercenaries book, am a Professional Thief trying to master my Special Forces skills. I've gotten Cyber Knight training, and finished the Headhunter Academy.