en_tn/2sa/19/06.md

nothing to you

This phrase is an exaggeration, but it expresses the very low value that David showed for the army. Alternate translation: "are worth very little to you" (See: rc://en/ta/man/translate/figs-hyperbole)

if Absalom had lived, and we all had died, then that would have pleased you

Joab is talking about a contrafactual situation. (See: rc://en/ta/man/translate/figs-hypo)