great, now we have a mutant soldier with two heads and four arms, holding a cut-off head of an alien.
in a previous version, the soldier with the head was "growing" out of the larger soldier below, where the neck and head should have been, resembling a centaur.
i mean, the face-covering helmet disappeared into the general mass of armor, and the two soldiers blended together in such way.
not that phalanx soldiers running rampage and cutting off heads of dead aliens and playing with them would be such a great idea in my opinion.
on some pictures it feels like the barrels are the most important thing in the picture because they are at the central location, and most detailed, and even cover up the firebird.
i think the barrels are superfluous.
on a positive note:
i liked the evening sky, because of the implied 'end of the day' message, as someone also wrote earlier (moon below cloud level, though).
but i think you are making it too complicated, either with the cut off heads or the barrels.
actually the last one (without the barrels) would get my vote (not that it matters much) if the soldier with the alien head was removed from the picture and the sky changed back to evening sky.
and, not only the weapons would need to be larger, but currently the firebird looks like some sports car, shouldn't the firebird be at least 3 times bigger, maybe even 5 times bigger?
and, i wonder how you feel about doing a parody of
http://en.wikipedia.org/wiki/File:Eug%C3%A8ne_Delacroix_-_La_libert%C3%A9_guidant_le_peuple.jpg or some other well-known classic, by copying some of the poses?