Remember, all,
if you are a target of a surprise attack, aka ambush,
that is a disparity of force situation,
and it allows you to use equal OR GREATER force than what you perceive your attackers have.
In other words you can immediately draw your weapon and fire.
Further if it’s more than one attacker, that is a second disparity of force reason and even if the DA or anyone else would discount it b/c you were ambushed, multiple attackers allows you to use greater force.
Always remember disparity of force. If you are weaker, older, smaller, injured, disabled, are surprise attacked, or attacked by multiple thugs, you can use greater force because every one of these situations puts you at an immediate disadvantage to your attackers.
...just don't be whiter than your attacker.