The SoC Training Academy and its Training Grounds provide basic training for new and old members looking to enhance their game strategy. "Train a Cook today, lose to a Sergeant tomorrow"
Last refers to the # of extra troops earned and deployed by that player in the Last (or previous) round.
Power indicates the relative strength of the team (or each player), for the current situation, on the map. I do not know how it is calculated. The # of troops, bonuses, and territories control likely play a role in the Power #. Someone may know and can tell us.