But what were your radioactive values at?
Couldn't that be because you're producing units that also require radioactives, but since the radioactives is depleted and negative, it stalls the production so the production does not use all of that metal? I mean, that's what I thought it was, but maybe it is a bug?
As for the health, doesn't it display the health of the entire army, so your dread actually has less hp than you'd think? Add a couple of hostile anti dread units and they can die very quickly.