Heat oven to 375°F. In a bowl, combine tomatoes with 2 tablespoons garlic, 3 teaspoons thyme, 3 teaspoons oil, 1/4 teaspoons salt and 1/4 teaspoon black pepper. Coat a rimmed sheet pan with cooking spray; spread tomato mixture on pan in a single layer. Bake, stirring once or twice, until tomatoes are soft and slightly charred, 20 to 25 minutes. Stir corn into tomato mixture. In same bowl, toss scallops with remaining 2 teaspoons thyme, 2 teaspoons oil, 1/2 tablespoon garlic, 1/4 teaspoon salt and 1/4 teaspoon black pepper. Place scallops on top of tomato mixture; bake until scallops are just cooked through, 12 to 15 minutes. Transfer scallops to a plate; cut in half. Stir vinegar and 2 tablespoons herbs into tomato mixture. Divide arugula, tomato mixture and scallops among 4 bowls; sprinkle with remaining 1 tablespoon herbs.
