I just flew EWR-FRA, then to BRU on LH. The connection was simple- a 5 quick jaunt through passport control, then security, and around the corner to the short hop LH flights. If your connection time is 2 hours in FRA, it shouldn't be a problem.
BUT- the key word is shouldn't. Things can always happen. Could you do your critical items as carryon?
For navigating FRA- listen to the experts and Follow the Signs. Do not think logically, just follow the signs.