I tried noodling around with a few different builds, but at least from what I was seeing it's hard to reconcile the skills needed for Goblin Shaman vs. Ogre Commander while staying within 50 Score and having Lightning Sword, at least in Nightmare. Going over it, I still think your best bet for beating the Commander Day 1 within 50 Score is going to be +3 ATK and Storm, which should let you drop the AGI requirement, allowing you to potentially go with +3 DEF (helps with dueling Quentin, though you can still lose with low damage rolls) and Slash/Pierce, +15 HP/MP, or Fire for extra area access.
In this scenario Slash makes it possible to beat the Goblin Shaman, but only if he brainfarts and attacks you (once, missing on a TA dodge) rather than casting Fire (twice), whereas Pierce lets you deal 40~50 more damage per critical hit to the Ogre Commander (at Lvl 1, anyway), and Fire gives you access to more materials and thus a higher potential max MP.
Of course, any way you slice it beating OC on Day 1 w/o Collar is going to require some measure of luck even if you are pulling out all the stops with skill loadout. Speaking from experience, there, as I've had that bastard hit me more than my fair share of times through both Tactical Advantage and Blindness.