The Doctor is not plying Clara with empty praise when he allows that she makes a mighty fine Doctor. He is dismayed. He is proud of her but well aware of what she had to give up in achieving her goal. He doesnt want her to be like him. But its not his choice to make. The Doctor may be creating soldiers but that doesnt mean hes littering the universe with mindless killers who blindly follow pre-programmed orders. On the contrary, he goes out of his way to engender creative thought. He wants his companions to question authority. Its up to them to decide what to do with the knowledge he hands them. If you cannot change the fact that there are times when one must fight then why not change how you define the person doing the fighting. In the series six episode A Good Man Goes to War we learn that in some cultures Doctor means mighty warrior. Should it not then be possible to transform soldier from aggressor to protector and healer?