Honestly, I am a fan of short fight scenes, they make it so each attacks carries satisfying weight behind it. Like, in a death battle each attack should feel like it can be life/battle ending, like things could end the very next instant, and if foes keep fighting for a very long time it's easy to lose that tension. Short fights also make it believable that no one else has time to notice and intervene. So imo, keep doing what you're doing!