The 16th century is old enough that some people groups went through name changes, and many of the names you are familiar with are not on here. This map also prioritizes the endonym (what they call themselves) name over any exonyms (what other people call them). Some exonyms are just anglicisations of the endonym (or another European language), or sometimes they are direct translations or the native name, or names from another tribe.

Apsáalooke means "crow" in the Apsáalooke language, so most people call them Crow.

Additionally, writing these names in the Latin alphabet is not always done the same.

I do find it hard that you wouldn't recognize more than one name, though. I'm no scholar, but I counted at least 140 that I recognized, and I'm sure I would recognize more of them under other names.

If there's a tribe who's name you know that isn't on here, it's probably because it was a less popular exonym (like souix, for lakota), or they didn't exist yet (like the Seminoles), or it refers to more than one tribe (like iroquois).