Hi Ben, congrats on your appointment, working on the field I would suggest a lot of wrestling drills, go to any number of wrestling sites on line and they will have dozens of drills, also the combat conditioning of Matt Furey is packed with activities you can do with just partner and body weight that will satisfy your head coach’s desire to work core, also there is a book on the ironmind site over body weight exercises that is quite useful, and the big one would be some strongman activities like tyre flips and truck push and pull, which you can set up relatively easily, they are also very competitive and may do the job for you as well, cheers,a shley