Old Trope
In any movie or TV show from the last 80 years, one thing stays the same with villains.
If there’s several accomplices, and one villain gets double crossed by another, there’s a good chance everyone is going to take out everyone else by the end of the show.
The formula works, because we all understand that people tend to act in the future like they did in the past (and part of being a villain is sticking to your mindset, no matter who it hurts).
If an artist asks you to replace a current member of their band, without first letting the band member go, run from that gig. We’ve all seen enough films to know what comes next.