A method for optimizing a generation of an output level over a selected operating period by a power block, wherein the power block comprises multiple gas turbines for collectively generating the output level. The control method may include: receiving current state data regarding measured operating parameters for each of the gas turbines of the power block; based on the current state data, defining competing operating modes for the power block; based on each of the competing operating modes, deriving a predicted value for a performance parameter regarding the operation of the power block over the selected operating period; determining a cost function and, pursuant thereto, evaluating the operation of the power block based on the predicted value of the performance parameter so to determine a projected cost; and comparing the projected costs from each of the optimized operating modes so to select therefrom an optimized operating mode.