I own a Katana and a Roman Gladiator sword mock-ups...
From looking at the pictures of the sword attributed to Khalid bin Waleed, one can't but notice the hellenistic influence, albeit the handle.
Obviously, the Scimitar is much like the Katana, but the curve is a lot more profound, which makes it more formidable when it comes to "dismembering" the opponent... Not very helpful if you are also trying to kick and box along with the sword fight.
For some reason, I have always found the Scimitar a bit clumsy, but it was a practical weapon for its wielder. The metal forming and annealing processes were also quite sophisticated considering the times they were made in.