Look at is this way: there are only so many ways to break a human being. If you're using your natural weapons, you can kick, punch, elbow, knee, throw, head butt, break joints or strangle. That's about it. If you add weapons, you're going to cut, stab, or bludgeon, or use the weapon as a grappling aid. That's all there is. Any martial art actually works is going to look similar to other arts that work. Arts that don't work can look like any darn thing.
A guy just won gold in the European Judo championship using a technique identical to one found in a medieval German wrestling manual. The human body is the same no matter where you go, or when you are.
Another thing you could think of is whether the art focuses more on seizing the initiative through attacking, or prefers to counter incoming attacks.