I remember seeing the final fight off this film as a kid... The possible super soldiers are wearing big (might be mechanical?) battle suits(its a group of them) and the final fight scene takes place between our main hero soldier and a villain soldier, in the mud and heavy rain. Also I think the love interest of the hero soldier is another female soldier, also in a battle suit. I don't think it's Universal Soldier, because I've seen it and it doesn't quite line up with what I remember...