Adjust standard oven or toaster oven rack to middle position and preheat the oven to 425°F (218°C).
In a medium bowl, whisk the tomato sauce, water, chili powder, cumin, sugar, garlic powder, salt, and pepper together. Taste, and adjust seasoning, if desired.
In a separate large bowl, combine 1 cup Monterey Jack, the chicken, 2 tablespoons cilantro, and 1/2 cup of the tomato sauce mixture.
Spread 1/2 cup of the tomato sauce over the bottom of an 9-by 13-inch (23-by 33-cm) baking dish or pan.
Brush both sides of tortillas with oil. Stack tortillas, wrap in damp dish towel, and place on plate; microwave until warm and pliable, about 1 minute.
Working with 1 warm tortilla at a time, spread 1/3 cup chicken filling across the center. Roll the tortilla tightly around the filling and place seam side down in the baking dish, making two rows of enchiladas. Pour remaining sauce over top to cover completely and sprinkle the remaining 1 cup Monterey Jack down center of enchiladas.
Cover the dish tightly with aluminum foil and bake until enchiladas are heated through and cheese is melted, rotating the dish halfway through baking, 25 to 30 minutes.
Move the dish to a wire rack and let cool for 10 minutes. Sprinkle with remaining 2 tablespoons cilantro and serve with lime wedges.