Depends on the character. Not all characters get the same exact bonuses from each stat. Most support-build (not actual support tagged) characters like EP, Plo Koon, and QGJ Tactics increase phys dmg, special dmg, and resistance.
But on the tankier build characters (not tank tagged) like Vader, JKA and Fives physical damage comes from Strength. For them Tactics only increase special damage and resistance.
For the more offensive oriented characters that are squishier like TFP, STH, Hoth Rebel Scout, Dooku and Maul the stat that increase physical damage is agility.