This is actually really great for a 4th attempt.
Id recommend some more dynamic lighting to give it some more shadows to make it seem less... plastic-ish, make some background too.
Havent worked with SFM for almost 2 years now, moved more to Blender, still not that much of a VFX artist but I try to have fun from time to time.

I thought I saw Kakyoin :(

And a lot smaller

Now its for soldier in-game

HOLY SHIT WE GOT A GLUBTANK!

...

gmod (:

WHAT THE FUUUUUUUUUUUCK?

U IN T34?

This one so far is your best one. The pose gives off the feeling of the scene. Good work here.