Grey is actually one of my better party members and I still amazed that his heritage of Warrior/Thief is doing better on his melee stats than Hawke's Martial Artist/Warmaiden. Granted, Hawke has like a hundred extra HP.

While I know Minstrel Song mixes things up with customization, the leveling mechanics are similar to FFII, so essentially anyone can be awesome if you take the time to level them, course this also tends to dissuade you from recruiting new people, except for the odd quest. I do know that starting with later entries, including Minstrel Song, their is suppose to be a stat preference scale that adds more variety to characters. In my SaGa Frontier 2 file, my main issues with Wil Knights was trying to play him as a melee character when his stat upgrades favored magic, so once I started playing him to his strengths, we got along groovy.

I will give you the warning Rez09 gave me about the RS1, try to avoid battles as much as you can, cause the quests available to you are based on a timer. Doing quests move this timer forward, but so do battles, so don't grind too much if you can help it in order to get access to the most story quests.