It is a fun detail. Maybe do a rule summary page? Something so the reader doesn't have to parse the rules out of the prose?
Good idea.
Maybe not in the book, but here:
JUNGLE rules summary
The referee is the final arbiter.
When in doubt, roll 1d20.
The higher the roll, the better the result. Skilled characters do more and better with the same number, compared to unskilled ones.
Sometimes the ref will decide to roll a d20 against yours.
If you roll low, suffer consequences. This is handled narratively.
Destiny Points let you either reroll, or you can avoid injury with them. One is usually enough, but the referee decides, according to the established narrative.
Weak opponents take one hit to die or be knocked out.
Stronger opponents have Destiny Points like player characters.