Hi Dan and thanks for your great pictures and question about the double leaders of your new ironwood tree. I'm afraid who you really need to ask is a certified arborist. They could tell you about the double leaders and also take a look and recommend which one to remove. There can definitely be problems in the crotch of trees with double leaders, so it's great that you are trying to fix this at this early stage.

Here's a website to find an ISA certified arborist near you, and you could even get several opinions and see if they agree!
https://www.treesaregood.org/findanarborist/findanarborist
Good luck with your tree,