Hi, thank you for trying our game! There's some strategizing that can help you win (other than the one you tried), but it's true it's left too much to luck.
I wanted to make something more balanced, with a couple more features that would've added a lot more play, but sadly I wouldn't have managed to code it in time.
About still getting betrayed... it's kind of intentional for the theme and the game's lore/context. It's supposed to bug the player a bit. I understand the frustration, though. If you want to share any other feedback or ideas on how to improve it, they're very welcome!