My Dream team would be 2 asari adepts a salarian infiltrator and human engineer.
CC basically all over the place
Human engineer I would go with a 6-6-6-6 build and don't put any points into incinerate and spec both overload and combat drone for maximum cc. (This is probably the easiest build to start with)
Salarian Infilitrator I would go with a 3-5-6-6-6 build. A little controversial but I would only put 3 points in cloak and 5 points in Salarian Operative. Make sure to take the increase damage by 25 pecent on the proximity mine.
Asari adepts I would go with an unusual 6-6-6-4-4 build putting only 4 points in Asari Justicar and Fitness. This makes the Asari alot more fragile but you have a lot more flexibility. Make sure to get stasis bubble for stasis, expose and weaken on warp, and recharge and force on throw.
Mass troops are bubbled and biotic exploded, Phantoms are stasis meat, Atlas mechs get shield zapped with overload and energy drain then hit with proximity mine and warp. Should go down quick under focus fire. Combat drone and overload make sure those guys you don't see at first don't get to close.
XBOX ONE GT : Omi43221