Definitely don't overdo it. As someone who's played grapple specialists, there are plenty of enemies that you either can't or don't want to grapple, especially as the level of the game gets higher. So while you might have some of the elite NPCs of the organization protect themselves with Freedom of Movement (or Heart of Water), leave some bodyguards/mooks/whatever for the grappler to maul, as well. Or just have more than one enemy, period. You can't grapple two at once, after all (barring very specific builds, etc).