There are four Guardians, each of them have a different symbol on their shield, if that helps as a hint.
Spoiler
Each Guardian exists in one of the four quadrants of the map, as indicated on their shield. So if you know where the guardian is in a quadrant, you know it is impossible to encounter another 7 there.
Too bad we can't do HTML in comments?
https://itch.io/t/2151831/adding-spoiler-text-to-your-game-description
Oh, I found a false pattern! Pattern Spoilers:
I thought the Guardians were like Minotaurs, but instead of 1 space away from a Chest, they were 2 spaces or something.