Underbosses don’t do dirty work.
They have roughly one hundred people under them they can choose from. And they have enough connections to outsource a hit to someone distant from their organization if they choose to.
Although that is risky. Unless the hitman is from far away and will fade back to wherever he’s from as soon as his target is dropped. Lots of people are doing long jail stretches because the indie gunmen they chose got busted, ratted, or messed the hit up.

Genovese associate Sal Delligatti is in the can until 2037 for something like this.