[HMM I OFF TOURNAMENT] "Company"

exactly, that's why I, for example, didn't know that: Player X lost to Player Y on Day Z.

Later, you'll share how it's done – then checking for compliance with the aforementioned rule becomes 100% accurate...

Added 3 minutes later

and also, I have two heroes in the tavern on Day X who previously participated in the game (playing as a team!!!)

Heroes are forcibly given only on the first day of the game or at the beginning of a save – after that, it's random – which needs to be controlled to ensure compliance with rule 1.4.