Thanks to you all for the appeciation, correction and advices, and especially to Chris and davbenbak1 !
I must admit that this is indeed a mistake. I based the whole group in 2011 and have left it unpainted since then. I had made no consideration at all of what each figure was meant to be doing. Now I have not only learned that I was wrong, but have also learned what should be like in the correct circumstance, thanks to your comments. BTW, I have also realised that the 2 loaders may also be too close to the muzzle to keep away from any fire and shock.
I'll pay attention to these problems in the future. Hats off to you, gents.