Personally, I almost always play with a buddy who is a Hunter, so to compliment his agility, I focus on armor and recovery, while using a defender sub class so I can act as a medic. When playing alone, I simply change my sub class to striker. As for intellect/discipline/strength. All of my armor values are split between armor and strength, but that's only because I like my armor, and I am just focusing on having the highest defense rating possible. You should keep in mind that the titan's jump abilities are shite, even if you are maxing your mobility.