With a rifle M1it's not possible to load a rifle grenade cartridge and a full 8-round clip, however it would be possible by loading the rifle grenade cartridge into the top of a partially filled clip, and perhaps judicious to load ball or armor piercing ammunition along with the rifle grenade cartridge. The rifle grenade cartridge would have to be manually extracted.
Advancing on a long destroyed armored vehicle with a smoke rifle grenade would only make sense to the photographer. This destroyed AFV was too good an opportunity to pass up for a photo opportunity, I certainly would have photographed it. If you think the destruction of the vehicle was a recent event it is obvious the weapons and the front wheel, and probably the bodies, have been removed. I reiterate the fires have been purposefully set in places where there was nothing that would burn.
Something you may want to take into account when analyzing these images, the photographers were rarely willing to voluntarily get too close to combat. The photographers usually sent their exposed film to the rear for developing and printing. The caption was often written long after the picture was taken, and often by someone other than the photographer, although usually from the photographer's notes. I have seen a lot of inaccurate captions that were obviously written by someone that didn't have any information other than the image to refer to, and the longer after the event the more inaccurate the captions usually are.
Comment on colorization: Movies and photographs that were filmed in "black & white" actually gray tones, were composed by the film makers and photographers to take advantage of the nature of the media. I don't object to the colorization of the prints if the "artist" has some concept of what they are doing, which is often not the case. I photograph in both B&W and color, both film and digital, and I appreciate that gray tones can often remove distracting color and bring out the subject better. I often digitally remove the color from images and find that gray tone images are more satisfactory to the composition than the color version.
FYI my last assignment in the Army Reserve was CO of a public affairs detachment. and in that capacity was trained at the Defense Information School (DINFOS), and reviewed many photographs for publication along with story articles. I am engaged in preparing the draft of a book and have spent days looking at prints at the National Archives in College Park, and have acquired many images, to illustrate the book.