Bonjour,
Yes, naturally, the nimchas of the privateers were shorter, as all the sabres of navy.
On the pics here under, 3 of the top are Nimchas (the first one for cavalry, second for cavalry or foot soldier and the third for marine).
The 2 of the bottom are Arabic saïfs (the first one for the cavalry and the second for marine).
The Nimcha of navy has a cut blade of baskethilt (discussion made 2 or 3 years ago).
Louis-Pierre