Depending on the soldiers' motivations, would it make sense for them to secretly adopt/publicly declare allegiance to 'the side that is going to win' ?

Would it make sense for one of the general's (probably Harry) to encourage their soldiers to adopt/declare this?

At this point, wouldn't it be stupid for draco/hermione to not coordinate their use of spies against harry? It only makes sense for them to agree to not use spies against each other.