Your reasons were the same as why ours are so close together. However, that is based on the fact that there is 7 years between my brother and I, and 5 years between my sister and I. I never felt close to either of them growing up and always felt left out, and didn't want that for my kids.

But that doesn't mean that it can't work for your family. I say go with whenever it happens and try not to think about it too much