You can Run the Servos but you cannot write it. According to Servo library in arduino main page it says - The Servo library supports up to 12 motors on most Arduino boards and 48 on the Arduino Mega. On boards other than the Mega, use of the library disables analogWrite() (PWM) functionality on pins 9 and 10, whether or not there is a Servo on those pins.
And I need to use that functionality of writing on to two other motors as well. I have heard of using a motor controller, but i dont know which one to use