Upgrading Little Legend Star Math Broken

I recently opened a support ticket with Riot to address and issue I noticed with the Little Legend star (★) upgrades in TFT. Here is the breakdown of the issue. I was the owner of a 1★ Dawnglow Silverwing. I hatched a 2★ Dawnglow Silverwing with a recent mission. 1★ + 2★ = 3★ being my math, I discovered that had only unlocked a 2★ Dawnglow Silverwing in my available Little Legends. Player Support told me that you needed 3 hatched legends to upgrade to a 3★ unit. Since you can get a 3★ from a single egg we KNOW that is not true. Does this seem right to anyone? Help? Am I just missing something?