Two Caidens? Sadness

So Caiden came home from school the other day sad as can be. He said that he can no longer be friends with his bff's Derrick and Gabe as there is a NEW Caiden (the new Caiden spells his name Cayden) at school.

I tried to explain to him that it is ok, and that they can ALL be friends, but he is really thrown for a loop at this other kid having his name. He feels like there is no place for him. I feel really bad for him. I tried talking to him, but I also don't want to work out his problems with his friends for him. I know he is only four, but I want him to start thinking through his choices and decisions. We have had numerous discussions over the past few days about this. He seems really distraught, and now has almost entirely stopped playing with Derrick and Gabe. He now plays with a boy named Cooper.

When I asked him why they couldn't ALL be friends he said "because there is already one Cayden there now", put his head down and walked away.

Dave and I intentionally tried to pick unique names for our kids because Melissa and Dave are just too common, and it really does suck when you have someone else close to you that has the same name. My best friend Melissa and I have the same name and we were called either by our last names or #1 and #2.

Suggestions anyone?? I want him to be able to work this out on his own. I have given him guidance, but don't know if I should force the interactions with Gabe or Derrick or this is just one of those "kids things". Help?!