Btw, the proportionality requirement in the law of armed conflict relates civilian casualties not with military casualties but rather the military advantage gained. The military advantages of killing a single low-level Hamas combatant are rather limited, and thus the room for civilian casualties should be rather limited as well.
There’s a whole lot of wiggle room in that phrase.
> The principle of proportionality prohibits attacks against military objectives which are “expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated”.
The way it's worded is to prevent destroying civilian targets for no military gain.