I akways try to get their Blade skill as high as possible . . at somewhere around 20 (25 with a GM daggar and an artifact dagger), they get so many hits per turn that the box at the botttom of the screen during combat gets so long that it goes right off the screen.I usually use 2 assassins so I can split their secomdary skills between them in order to be able to put more points on their blade skill.
As you found out, a Gladiator with 2 spears at the GM level gets 6 hits per turn which, if they're artifact spears, the damage can be awasome.
My favorite team is GAAP and with that team I can kill the mega-dragon in pure melee RT without any magic except healing.