It looks like the fire claws have a slightly higher ego, the wyrmhelm the lowest, and all the rest about on par.
The given powers are...
The Fire Claws: Function as bracers of defense/ring of fire resistance.
The White Shield: Damage reduction 10/-, +4 bonus on saves vs. cold. Dragons won't attack wielder.
The Venom Lance: Venomous, detect good 1/day, cause fear 1/day, and communicate empathically with its wielder.
The Cloak of Clouds: Feather fall 1/day, gust of wind 1/day, fly 1/day, lightning bolt 1/day, control weather 1/day, "electric shield".
The Wyrmhelm: Allows wearer to speak draconic, charm monster (dragons only, no save) 1/ week, command 3/day.
I'd say that all have the special purpose of "form the Taumet", so I'd suggest breaking them down the mental ability scores as follows...
Wyrmhelm: Two at 17, one at 10
All Others: Two at 18, one at 10
Fire Claws: Two at 19, one at 10