There's some extra calculations that you need to do.
The M433 does a maximum of 25 damage at 830 rate of fire.
The SL9 does a maximum of 25 damage at 675 rate of fire
That's roughly a 22% difference in fire rate. Also keep in mind that you need a minimum of 4 body shots to kill, or 3 headshots. So it's unlikely that you'd kill anyone with only 3 bullets.
It's also a matter of damage drop off. The SL9 is a SMG, so the damage drop off is quite severe. the M433 is an assault rifle, so it has less damage drop off at range. This means that at >10 meters the SL9 requires 5 shots and somewhere around >40 meters it would require 6. On the contrary, the M433 has a 4 shot kill upto 20 meters and has a 5 shot kill upto around 80 meters.
Why this difference you may ask? Well, it's because the SL9 has far less recoil and spread.