So I'm bored, and don't have early access. When you can't play SWTOR, the next best thing is to research something. I used a Raid Composition Builder on Sith Warrior and played with a few things. With as a few as five players we can fill all of the raid buff slots. Some of these buffs are provided by the Base Class, and not the Advanced Class. The Damage / Healing Bonus as an example is provided by Jedi Knights. If we have an encounter without a Guardian tanking then that buff is still covered by a DPS Guardian.
After covering buffs with these classes we can bring, as an example, an extra Direct Healer, or a HOT Healer, etc. and better flesh out the raid.
Jedi Guardian Tank - Damage / Healing Bonus, Accuracy, and Armor
Jedi Shadow Tank - Damage Reduction (Internal / Elemental), and Stat Bonus
Trooper Commando Heals - Damage Reduction All, Armor, and Endurance
Jedi Sage Heals - Damage Reduction, Stat Bonus, and Armor
Smuggler Scoundrel Heals - Critical Hit %