I think the author of the linked article might disagree with the claim of historical accuracy for that novel. He wrote at length about Pressfield's misconceptions.

https://acoup.blog/2021/01/29/collections-the-universal-warr...

Gates of fire is a great book, that I would recommend. But it’s a novel. The Spartans didn’t really write anything down. All the character interaction is great, but cut from whole cloth of the author s imagination. It’s a great story. The big fight might be accurate, but about as accurate as a third hand account.

But yes, I really enjoyed it. Good book.