I soloed alot whenever I first started the crucible but with my Titan I still have a 1.77 kdr(which for a solo player ain't bad) but I can usually get a 1.5 or 2 kdr in crucible the key to the titan is to hit the enemy where they least expect you say your whole team is going one way and you know most of thier team is gonna go that way to. Take a different way and flank them to be completely honest I've wrecked whole teams even just charging in. Warlocks and hunters are easy to use in the crucible but if you master the titan you k ow your good. Just keep practicing eventually you learn how to read the combat and when it's a good time to pop your FOH. Also lightning grenades omg lightning grenades FTW.