guerrilla:
dmr
assault rifle
frag
thruster pack
firepower
dexterity
allows for a near seamless transition between various ranges. I've found thruster to be the ability that has the most versatility. whether it be short or long range, attacking or defending, chasing or retreating, combat or just map control.
doppelgänger:
dmr
boltshot
plasma
hologram
aa efficiency
sensor
here you would rely on the hologram for both offense and defense. you see where enemies are on the radar before they see you, and you can get a general idea of their direction of travel. use the hologram as a decoy and flank around, those seconds it fools the enemy are precious in halo 4.
duck around a corner and a lot of enemies will follow you. that second or 2 of time they can't see you, send a hologram out. either back toward the enemy, more often than not making them spin around to attack it and expose their back to you. or send it away from the enemy at a wider angle than you would be traveling along so they see the hologram first