Not really, but I'd keep it in Town Hall Vault.
The nanocobaron sword is a major step above the Paladin's Sword in terms of damage range, dps and even elemental damage. Both swords have the same speed and crit and both are 1-H weapons. It would only make sense to not give Hirge (or your Companion) the nanocarbon sword in two narrow situations: 1) Against enemies that heal with bolt damage (which is Invisible Swamp Donkey rare), 2) When the player is using batteries in the backpack for the player's EMP weapon and doesn't want to share with Hirge (wait, do Companions even trigger emp with batteries, I haven't actaully tested that point).
The Nanocarbon simply far more damage than the P-sword so even against undead or bolt resistant enemiues, the nanocarbon outpaces the P-sword.
Nanocarbon Sword:
http://www.exiledkingdoms.com/wiki/inde ... rbon_Sword
Paladin's Sword:
http://www.exiledkingdoms.com/wiki/inde ... _Longsword