Perhaps you're not playing it properly? Enemies tend to take a long time to fell if you are not focusing on their weaknesses or staggering and then upping the stagger multiplier. You're really intended to use all your moves synergistically and be switching between characters to build ATB. With the synergy skills and abilities the combat has gotten a bit more complex in the sequel

From what I've seen the combat is considered one of the strengths of the remake series.