Normal battles are not too bad except in places where enemies call for help or can respawn like the smurfing undead... You seriously can't win against overwhelming numbers sometimes. Beyond that, I found the Hunts and boss battles to be fairly challenging and enjoyed coming up with new strategies.

Bolivar: I kinda noticed that too. He's not very powerful but he seems to move so fast sometimes he can combo moves. I've had a few battles with him where he nearly overwhelmed my party not to mention his use of the palings can throw a monkey wrench into your plans sometimes. I have high levels and endgame equipment and he can still be a handful so I do wonder if his Gambits and stats are slightly tweaked depending on your levels or progress in the game.