You seem to know a lot more about ordinance than I do but from what you’re saying, it sounds like tungsten that is not alloyed with thorium would be the way to go!!
I wish there were more international cooperation on this stuff.
My parents’ generation all seem to hate benzene and warn us it’s toxic as hell. That’s the only time it seems to come up, might be to do with napalm now that you mention it. Much shorter life and half life I guess.
For what it’s worth I also think deliberate napalm and white phosphorous use on humans are war crimes as well.
A couple of years ago Indonesia used white phosphorous on some West Papua villages and the results were horrific.
Edit, just realised I forgot to answer your first question. I do not recollect the details about the relative proportions of other causes of birth defects etc in that environment but I would argue that a) DU alone definitely earned its place as an unethical weapon and b) any known risk factor with that high a contribution should be phased out too.