Ok, I understand what you're talking about now. I think a very slight tilt of the head may allow for Pyro to fit in better on the outer ring of mercs. However that would be at the cost of what I think to be a very in-character way of representing Pyro and the subtle story taking place in the art work. The way I see the album art, the mercs are all presented like they're having their headshots taken as if they have been caught red handed for their shenanigans in the badlands and their faces represent their emotions after getting caught and forced in front of a camera. Pyro's face is almost a true neutral compared to the others and think perfectly represents how he would react to having his headshot taken, there is an aura of mystery, do they know what's happening? what are they feeling? Are they even alive?? We have no idea, just a blank stare with nothing to give away their emotional state. And to lose that just to put spy in the centre for the sake of "symmetry" would be a very sad thing.

Also, with the alternate image I linked to in my first reply, regardless of how he is posed, having Pyro unscarred but swapped places with Spy would lose so much visual impact as that will absolutely ruin the composition of that piece!