I figured the issue with Raul and Rey wasn't they were a clone its that they basically age to death. As the clones were created and had to age faster in order to be pilots of any worth sooner. This is mainly presented in my eye's by Rey growing from being a little kid when he was with Raul to 3 years later him becomming a full teenager and a MS pilot. In my understanding the pills have just been a way to slow the aging process to a more acceptable rate however as they are constantly aging at a much faster rate then a normal human they will die much faster.