Think it looks like a good start!
The textures look pretty cool.
The Walk cycles kind of let it down a bit, and I think that more work on them would definatly make it look better.
Also it is just one clip that youve rendered form different angles? as the same actions appear to be happening over and over. If it is that youve rendered from various angles I would try to stretch it out as it lacks continuity because of the repeating motions (tanks being dropped down is one thing that I noticed).
As for doing something like this I would render it in layers, background, tanks, helicopters, and then the people, that way adjusting the walk cycle would not require rendering the whole thing over again.
Cheers
"No pressure, no diamonds" Thomas Carlyle