Wait, so you have ICs who work on multiple projects, and report to a different manager depending on the project? That sounds like a nightmare. Having one manager to manage is usually enough work...

In the company i work at this is the standard. Its all pure waterfall and its dreadfull

It's actually quite common and it's called "matrix management". Multiple people to give you orders and no one to take accountability. You'd be surprised how wide spread it is.

It's chaos. This is standard corporate management in 2025 though.

It’s generally just fine if they all boil up to the same manager and that manager has a direct line to that IC.