en_tn/pro/18/09.md

one who is slack in his work is a brother to the one who destroys

This speaks of the one who is slack being similar to the one who destroys as if they were actually related. AT: "is closely related to" or "is very similar to" (See: rc://en/ta/man/translate/figs-metaphor)

is slack

"is lazy" or "is not interested"

the one who destroys the most

"the one who destroys everything" or "the one who is always destructive"