This some really good stuff, and there's no doubt a lot of work put into this. Though, I'll post my opinion on each animator.
Kewell; Your stuff is no doubt, the best here. The animations look smooth and especially the part on the rooftop. Though, it's odd the fact that the assassin is a little too detailed compared to the rest.
Chaos; the animation is pretty good here too. The background could've been better though. And lastly, lever-action rifles in that time setting isn't fair (lol).
Wop, Animation wise, it's pretty good. Design wise, minimalistic sure, but too minimal.
MCCrazy's animation seems to be my favorite here. Kinda sad there's not that much of it.
Sunhang animation is quite simple, I like it. I like the concept of a Smith agent as an assassin. Again, with MCCrazy, there's not that much I can talk on.
Overall, This is a pretty good compilation of animations. All animations look really smooth though some slow-down (leading to a slow and awkward kill) is there.
This deserves 4.5 stars, Keep it up guys!