What you’re trying to do is API abuse. Stop it.
The reason the /v1/games/{placeId}/servers/{serverType} endpoint doesn’t return user information is intentional to prevent external users from viewing the players in a game server without joining it.
Player tokens are a unique user identifier meant to obfuscate the actual user ID. You can’t resolve user information from them.
It’s also not possible to resolve user information from their thumbnail - even if you somehow had the processing power to generate a thumbnail for every single Roblox user, multiple users can have an identical thumbnai, making it impossible to be certain of which user a thumbnail belongs to.