>Well, they weren't trying to kill him, but they were going all out in an attempt to knock him out
Headcanon, they never were going all out against Garou, Bang was being more ruthless yes but not going at full strength.
>because they knew that their full power would not kill Garou,
Bomb literally threatened Garou, he knew he could kill him if he so much as wished it. Bang on his part was teaching Garou a lesson for being an ass.
>but even that didn't finish off Garou as Garou could retaliate against them right after they barraged him with full power, plus,
How would he retaliate exactly? The AP gap and skill is something he can't make up for against Bang, let alone Bomb.
>Garou was severely weakened at that time, making the feat EVEN MORE IMPRESSIVE.
The only impressive thing is his stamina, nothing else.