Septimus has a full complement of intensely powerful elemental magic (air, earth, water, fire, wood, metal), plus he can read emotions and to a slight degree project them, and he's a terrific swordsman and tactician.

He is not so used to this particular kind of teamwork, but he will definitely be able to take quick measure and come up with tactical suggestions, though if anyone wants to improve on them with creative pragmatism, go ahead. He relies on himself and his talents too much.