Adding Clayface is totally missing the point. Creature Commandos is about the question of losing your humanity during war. And as the CC are monsters, are they human to begin with?
A vampire, a frankenstien's monster, and I think the creature from the black lagoon. But they were all born human. A blood disease, surgical reconstruction, maybe an exotic serum for Mina. Now they have fallen from the grace of the lord's light and are unfit for society, or something like that.
plus a squad sargent who's racist against all of them. I guess to show off the human qualities of the CC's, and the subhuman qualities of the common hateful man.
Is DC not able to do a straight WWII movie anymore? Get some army uniforms, a few nazi uniforms, some deep dialogue lifted from the comics and some Shakespearean speech because that was the style that upper class had at the time. Run around and shoot off some squibs. Lament their actions and the war in general. Get it together for the day of a push into some sector. Win, oh horrible victory. Set up the sequel. Roll credits. No one needs to fly, or have newer monsters. They may be reaching "undefeatable Batman" levels of super-actions but that's part of being the monsters. They're too _good at_ war for the war effort to let them regain their humanity.