I like the idea of Templar, as long as it has a different background and different abilities.

The Paladins were once the elite of the Sultansworn, who vowed to protect their homeland, Ul'dah, and its Sultanate. However, times have changed since the rise of Adventurers. The long period of uneasy peace following the Mor Dhona incident eventually gave the impression to the Sultanate that Paladins were of no use anymore, so they lost jobs and position in Ul'dahn society... until 5 years ago.

Perhaps the Templars could be from a distant land? Why not Ishgard? Perhaps the Templar could be a super-religious order if Ishgard.