Very cool. I would suggest strengthening the shadow under the men's feet to match the shadow strength under the photos, as they look a bit like they're floating, and I think the front leg shadow(front guy in red) needs to be drawn closer to his foot. Very nice idea!

Pretty cool...

Just suggestion try with different background!

Using good background may change it to more reality.

Best of luck my friend.

thx for the comments and tips, i added soms shadow at feet and think bout another background, any suggestions?

Hi my friend,

I will suggest to add some grass field in the background as there is lots of grass shown in the images but do remember to add character shadow on the grass.

Try to search grass on - http://www.sxc.hu/

Hey nice idea, execution could be better.
What could be better?

The grass the people outside the frame are standing is all blurred out.
What would make it more realistic
(even tho the entire composition is not a realistic one you probably want to archive a realistic like look)
is having grass wich is in focus ( non blurred grass ).
If you can not manage to find the right grass with the right focus and the right angle,
try taking a large image resize it smaller and distort it in the right angle. If then the image is too sharp ( to much ofcussed ) you can use a little blur to get the right focus.

Also you might want to try to add some sand under their feed like in the original.

Also one more thing, im not sure if you linked teh right source.

I hope it helps you, and im only giving advice from how i see things.
If it does not help you just ignore me.
That beeing said.

Good luck.

thx for the comment photoshopper specially bout the source link, added the wrong one almost got removed of it

Super cool idea author...best of luck