So my friends and I just recently started the game and went for a little tournament of our own, between the five of us (totally Casual and uncompetitive, besides the demeanors, of course :D).

In one of the last games of the day (didn't have any time restrictions and haven't played that much, so a game could last for 3 hours) we had a situation, in which both players reached zero honor, after bidding in the drawphase. After looking through the RRG, inquiries to Dr. Google, and a quick forumsearch, we couldn't figure out what to do.

The RRG says the drawing happens simultaneously, and we are unsure wether the simultaneous rule applies, since there are no decisions to make?

Does the rule apply and first player drops first? Or, if not, is there another rule that applies? Or an official ruling for such case?

Thanks in advance!

Check the RRG, under "Winning the Game"

https://fiveringsdb.com/rules/reference#winning-the-game

If both players would reach a victory condition simultaneously, the first player wins the game.

This will shortly be updated to:
If two or more players would reach a victory condition simultaneously, the first player wins the game if they have reached a victory condition.
If they have not, the player closest to the first player’s left who has reached a victory condition wins the game.