Well out of four Dukes; Aryabhata seems to be most appropriate to lead Tytania. Salisch and Idris are too caught in past Tytania as it went establishing itself (by massacring people labeled as rebels), while Jouslain is neither in past or have any vision for future. Only Aryabhata has any chance to develop himself into strong leader while other have too strong of character to change themselves.
PS Tytania deserves to be in Series En Fuego: sub-forum as it has much to reflect on each episode.