Legion XIV is good making things disappear fast with Hammer Barrage. Legion XIV is not an endurance fighter, but (with dumb-fire missiles) more of a fireball wizard. That said, I probably would not use either Legion in an Ordos hunter fleet. I would not use homing missiles on Legion XIV, Conquest can do that job and fight better. What Conquest cannot do very well is drive up to enemies and unload Hammers or Reapers at them. Legion XIV can do that. I just wished Legion XIV was not the only ship that can use dumb-fire larges well. I suppose Radiant for those with Automated Ships skill next release can do that, but getting a single tier 5 skill like that is a huge price.
Hammer Barrage is one of those fairly common weapons that can be found in Open Market. I just wished there were good ships that could use them effectively.
I use normal Legion like a dreadnought with fighters. Big guns only (thanks bad dissipation) and fighters. If I want a 40 DP capital with just guns and missiles only, I use Onslaught or Conquest.