Hey Jerry tremendous combat scene, I think we’ve noted before that when figures are out-of-focus that’s usually a very Good Thing because it suggests movement & yours is a classic example, brilliant. But regarding the focusing problem with the tanks, one solution would be playing around with different lenses but I believe like me you prefer to keep things (& photography) simple with a single-lens device. I’m not sure what you’re using but if you’re uploading to your computer, it’s presumably via a software program that ought to allow cropping of images. Please forgive the photo-bomb but to illustrate…
The first image was itself cropped down from a much wider view because I stood a couple of yards away, which allowed a greater depth of focused area. The second image is a further crop-down - the risk of course is that some definition is lost but I think that can contribute to an authentic-looking war-time photo. Anyhow the point is those Ferdies in the background were 2 or 3 feet back from the left-hand Borgward, yes they are just off-focus but I like to think by around the right amount. Maybe hopefully you can pull off the same trick? 
(In fact the nearmost Borgward ain’t in focus either (!), the Mk III is, but standing off from the scene allows better overall focus)