Would be kinda pointless you would never or rarly ever be in close distance to another player.
The Shocklance worked because you where chasing big fat heavies around and as it was a 1hit kill.
this is why i said a sword with the ability to enter overdrive at will. The speed from overdrive will allow u to dash quickly at the enemy for a hit.
but it seems theres no way getting around the shocklance with you guys

that thing was boring for me.
a weapon to give you overdrive... thats sounds like it would just ruin the object of overdrive as i understand it Overdrive is something you get when going at a certain speed you get a speed boost in one direction but it costs you health?.
The only way I can see a true melee weapon in tribes working would be if you had Full conrtol in the air and infinate energy and had your manga style midair sword/axe/whatever fights.. maybe a idea for a mod.
I my view any weapon in a 3 axis shooter should be designed to keep the fights at quick speeds and not slow movement down. IE medium ROF projectile weapons ie arcing grenade launchers for ground targets Rockets(cant help it Disk launchers) for midairs and also a Chaingun/mini gun for pursuit

and Laser snipers(the only hitscan weapon) for some nice gh3y osniping.
There the 4 main staples of the genre, you then add in extra for different gameplay ideas, Blasters infie ammo good spawn weapon, Missles for against Vehicals(if added) Base assest killers low rof high dmg morters etc.(again if there added)