Actually, in my opinion at least, Tifannys powers fit her to a T, yes she is cold(arguable?) manipulator, essentially the poster child oh a machiavelian prince(ess).
A leader, organizer, (since that is what her father is grooming her for), someone who stays in the backline and directs. It is precisely her cold, dispassionate personality, ambition, drive, intelligence and work ethic that would make her a perfect strategist, bolstering the front line, analyzing the enemy and countering them.
It is also why I believe Michael would be a better team leader than the mc. He is a natural born strategist and tactician, couple that with his years of experience and ability to keep calm and focused in dire situations that would make him awesome as a leader.