Well, it could be a trainer but not a melee trainer- honestly, I am with Grayson on this and WHY would you want to encourage your new pilots to engage in melee attacks. Shoot the ###### and try not to get hit is the name of the game. So IF I was a militia ordering this to fill in a light lance and it would be often tasked as part of the training force, then I am removing the mace so I can give it another weapon and making use of handheld weapons. If you ignore the melee, then its not bad as a trainer- basically right up there with the Stinger/Wasp options in that its 6/9/6 with a few guns and decent armor for its mass.
Melee training is actually useful for enhancing piloting ability, as well as emphasizing use for the large amount of hatchet, mace and sword mechs the LCAF has its inventory for physical attacks. Another example in universe is the pilot training the 17th Recon Regiment uses in the 1st Camachao's Caballeros novel, where better piloting is emphasized through physical attacks, jumping, and so on since the Caballeros can't produce the gunners the more potent merc companies like Wolf's Dragoons or the Kell Hounds have. Heck, in the Dark Age even the Jade Falcons have moved to using Talons for DFA and kick attacks. I'm sure there is a melee attack specialist ability that helps with piloting rolls or subtracts from the TN needed to hit with a melee weapon.
Use your jump jets, boost the TSM, and whack the enemy. It's a high risk, high reward maneuver, just like Death from Above. Given the LCAF's cavalry companies scouting for the wall of steel, a quick elimination of another light unit weakened by your lancemates' fire via a melee attack makes sense. So does make sense in that context, especially with mechs like the Hatcheman and so on. Does it meet the fluff from 3085? Nope, but that's simply how the design was presented to the LCAF, and they bought it. So did other powers and mercs, which isn't surprising.
Militaries in real life buy overhyped lemons all the time.
I would use it the following roles
A gladiatorial mech
Training mech for pilots with a natural bent for piloting and a hotshot attitude towards physical engagements
Raiding with faster mechs that don't have jump jets, or have the same speed and need close up cover, like Stingers or Wasps
Garrison duty in low to medium security sectors
Punishment duty for Mechwarriors who need examples made out for them why you don't try to seduce the Hauptmann's kid
A demonstration piece for visiting nobles and social officers in the LCAF, or for merc companies that need a wow factor for people to sign them on.
Cannon fodder against superior forces.