It doesn't matter, the first push establishes a 2000fpm climb rate. If you are in windshear the engines will automatically go to full power to try and achieve that. That goes for autoflight. In manual flight pushing the toga switches will activate the windshear escape mode of the flight director, the auto throttles do not move and hence you have to push them full forward yourself.
Edited, red the QRH, last statement was incorrect!