This is just my opinion about Last Blade 2, and granted I'm not the biggest fan of that series, but I thought the first one was a lot better.
Will you enjoy the 2nd one more if you play part 1 first? I don't really see how, because part 2 is a beautiful game in its own right. I'm partial to the first one because I thought part 2 was a little too frustrating (the cpu characters, from the third fight on, seem to deflect every single swing you make at them). But then again, my taste for fighters goes the way of KOF and Real Bout, so maybe it's my skill (or lack thereof) that makes me think this way.
This isn't to sway you at all from a work of art like Last Blade 2. Definitely pick it up. It's no where near the hack-fest of SS4 (which I liked better too), but it's a fighter that'll challenge you to worry more about planning out a strategy, and outwitting and out dodging more than connecting hits.