Is it possible?

As a parent, we try very hard to raise our children to be nice, polite, well behaved little angels. Very rarely does it actually happen but it does. We teach them to share, be considerate, take turns, use nice words, say thank you and please....But is it possible that a child can become TOO nice? I am noticing that Troy is always the child that gives in, gives up his turn, follows others even when he REALLY wants to do something else, and I just wonder if maybe I need to teach him it's okay to say no (to others, not me of course). Sometimes it just makes me so proud to see that he's willing to give something up to make someone happy. For example, my mom has 2 huge frisbees that all the kids like to play with. Troy had one and Will had another, but my nephew wanted one. He started throwing the typical 2 year old tantrum and nothing worked. Troy went over and gave him his frisbee and found something else to play with. It was the sweetest thing to see and all the kids were just happy. But other times, this actually makes it harder to teach Will (who's really showing his temper lately) because he'll get mad when he doesn't get his way and I try to teach him to be patient, wait his turn, or whatever the lesson of the moment is and Troy will come in and give Will what he wants and everyone is happy. This is great in some ways, but in others it's not helping with Will's tantrums. Sometimes he doesn't like giving something up, but he's just so willing to do it to keep the peace that I wonder if he'll be able to be assertive when he really needs to be. I actually feel silly even questioning it because he's such a good child and so very sweet and caring (he's not perfect--he has his moments of course, but overall, I can't complain) but as my father always said--"You have to find something to worry about, don't you?" Yes, Pop, I guess I do.