Should kids have best friends?

Here is yet another article that I have an opinion that I want to share. Don't really care if it fits the article or not, but it draws from my personal experiences as of now.

My 6 year old has a best friend and some stand-in best friends, and then some kids that he knows but doesn't really have a strong opinion about. And I'm sure there are also some kids he just flat-out doesn't like, but I have yet to hear about those and unfortunately, I don't have time to hover around the playground and intensely scrutinize his interactions with the other kids. Some of that attitude is my generally hands-off approach and some of that is the fact that he is his own person and I need to let him learn to deal with people in his own way.
And he is a boy. Boys generally don't have such cliqueish issues as girls, and especially at this young age, although it is easy to see the beginnings of the social climate being formed.
Along this regard, I have been struggling with the camp placement in groups for this summer. One reason I choose to send him to the camp I do is that he has an opportunity to break free a little bit from his religiously structured private-schoool existence and to intercact with some friends that he knew before we forced him down that track. Somehow, even despite my request to the contrary, and that he be placed with those kids that are not part of his everyday life at the moment, he was placed with the private school kids. It hurts my heart becuase I wanted him to be with some old friends from preschool that wouldn't let him onto the baseball team I wanted [because it was already full] and it caused this season to be pretty awful, whereas they had a fun time all season.

However, the playing field with my 3 year old is even more pronounced. She has her friends that she likes and they like her [thank goodness for that] Then there are the friends that she likes that don't particularly care for her [ouch] And of course there are those kids that she just doesn't like [also ouch] She is on the small side in stature but a force to be reckoned with in her personality. She is already getting her feelings hurt when some of the larger kids refer to her as "baby" This week I taught her to parrot that most all important phrase of small kids everywhere "Good things come in small packages" Of course, she doesn't comprehend what the words mean yet and half the time she can't quite get out the whole phrase, but the foundation is being poured. At least she will have something to say that won't exacerbate the situation when she gets a little older.