Yeah - I've never really liked the laying-down clone sculpt either.
If they needed a third "pose" why not have the clone standing at attention like at the end of AOTC when they're all lined up to start loading the transports. To me THAT would be a better pose then laying on the ground.
Not really disagreeing, I never noted any lying down during the movie, but this pose isn't that unusual, just unsuitable.
Way back in the day, we used to get generic army figures in multiple poses, zero articulation. This guy is a hold over in someone's mind for a sniper from a bygone era. I probably get more of a kick out of it because it simply reminds me of old toys that I used to play with as a kid.
That said, the sheer expendability of clones in AOTC has always bugged me. I realize they are clones, but were their minds turned off completely. Some of the battle formations must have surely resulted in multiple casualties from friendly fire. If one or two were actually bright enough, I think they might have lived a fair bit longer than their compatriots leading the front edge of the charge.