I was able to track down the source that said Cecil was an easy character to start with.

Cecil -- “Style Maker”
His ability to switch between Paladin and Dark Knight allows him to excel at both Air and Ground style combat. He appeals to beginners because he's not limited to one style. Most of his attacks have auto-targeting, combined with his strength, beginners will most likely flock to Cecil.

Recommend: Starting Players who don't wish to limit themselves to one style of fighting.
What they said about Cecil as well as this
Warrior of Light -- “All-Rounder”
A difficult character to start out as, as all of his attacks are linear. By linear, I mean when he's directly above or below his opponent. His greatest attribute seem to be his defensive nature. Forcing the player to know plan their attacks carefully or end up beaten by a faster player.

Recommend: Advance Players, with a good sense of timing.
got me thinking that Dissidia's fighting system is so complex that the "well rounded characters are good for starting out" rule didn't apply to this game.

I just felt like posting this since I wasn't able to cite my source last time.