S.E.
Your son came into the world with exactly the personality he is suppose to have so as far as making him "tougher" he will learn and decide for himself what is worth fighting for. I have two sons 7 and 3. The each have developed completly different from each other; my seven year old sounds like your son he was very much a mommas boy and soft at heart. He still is both of those however, as he has grown he has developed as sense of right and wrong and what actions if any need to be taken to guarantee that for him. All children especially boys get this on their own time, your son will probably learn very quickly in daycare how to defend himself. You should tell your husband that you are not raising a bully and when your son feels strongly about something he will see a different little boy emerge. If he has been staying at home with you since birth (good for you!) then he probably has not been in a social setting on a daily basis that requires him to have developed this skill yet. Take it easy it will come.