I don't care much, but I don't like it either; I was thinking today about people who name their kids "Erin Amber Aura and Erica". When you have to shout up the stairs, how can anybody be sure which name it was you hollered?
If child1 is always Kaiden & child2 goes by nn Cal that's a bit different.
Ds1 has a name very similar to Kaiden and ds2 is Caleb. I think their names go great together but ds1's first initial isn't C or K, and they have nicknames that I use more than their 'proper' names so it doesn't matter how they sound together.