For example, the helmet of the "look sir droids" is the same of the dewback rider and one of the troopers in the docking bay shootout, but the armor has different set up. I believe there were only 6 full suits for the tattoine scenes Sent from my GM1900 using Tapatalk
The reason that happened is because between shots, the actors playing the sandtroopers will take off parts of the armor and pile them on a corner until is time to shoot again during the undressing and dressing process some actors will switch pieces without noticing the mistake or worrying about it. There are many of those cases during the few minutes we see the sandies on screen Sent from my GM1900 using Tapatalk