These guys are right after the Bahamut and Levithan dudes. So I'm giving you another bonus.
Doga: Doga (and Unei, right behind her) is an easy enemy to defeat. With our party of a Black Mage, White Mage, Knight and Monk, we killed her in two rounds with little difficulty. How did we do it It's simple, really. Our physical attacks were extremely effective, and we cast Bio on the foe with our Black Mage (our White Mage defending or healing each time). Two rounds was literally all it took. As far as Doga's attacks, we were attacked as a party by a Blizzaga spell, and had a few physical attacks (two attacks per round). Otherwise, it was as simple as could be.
Unei: Unei and Doga are really the same, and fighting them provides the same experience. We used the same attack strategy with our particular party (physical attacks, Bio, healing/defending with our White Mage), and it only took us two rounds to defeat Unei as well. A Tornado attack was inflicted on the party during the fight, but it's nothing a party-wide Curaga can't take care of. The only unfortunate part of this battle is the fact that Unei will attack directly after the battle with Doga is done, so there's no time to heal or prepare. Simply cast a party-wide healing spell of your choice on your party as soon as the fight takes place to relieve that problem. Otherwise, this battle should be extremely easy for you.