Yes, I think so. The verb forms (am, is, are) imply existence or equivalency and not action, i.e. the noun or pronoun at the other end of the verb is not receiving action. Hence, it would be correct to say, "I am he" (awkward as it sounds. the more common expression would be that's me technically incorrect but so widely used that no one would call you on it anymore.) It would be correct to say "I hit him" not "I hit he" because hit is an action verb and the receiving pronoun must be objective.
BTW, I'll take this opportunity to air one of my pet peeves. People, particularly those who consider themselves well educated very often say "between you and I" which is wrong because between is a preposition and the following pronoun must take the objective form.
Regarding my German studies, I hit it pretty hard and regularly for awhile, but haven't done much lately and so I'm losing it. I must get back on it.