Hello there! Appreciate the question! I will start by saying that the shoe is designed to be worn with one insole only. Although insoles are thin, they still take up volume and that is why the shoe felt so snug.
Sometimes manufacturers include an additional insole so that when one eventually wears out, you already have a replacement. Foam insoles will break down eventually and before the outside of your shoe. In order to get the full lifetime of your shoe, switching out the insole is a good idea.
If the two insoles they sent you aren’t identical let me know.
Hoping you get many more miles put down in your new boots!