Well to be fair, Tony obviously did sense something was up with Johnnys plan, hence why he didn't go through with taking out Carmine.

Taking out Rusty was IMO a way to keep Johnny happy so that maybe he can keep some control over Phil.

So I'm not sure Tony was the worst boss ever depicted. There are plenty of mob bosses who have been significant characters on screen worse than Tony. But despite making a few smart, calculating moves, such as making Junior a lightning rod, i think he was a pretty bad one. There are a number of questionable decisions made throughout the series. Of course hindsight is 20/20 especially for a fictional show, but I too agree there should have been more internal tension regarding the whole Tony Egg thing.