After decicco died the underboss position was vacant so for the time being gotti filled the posstion by naming gravano and ruggiero as co-underbosses then named Joe Piney as underboss
I'm not sure where you are getting this information but it isn't correct. Ruggiero was already on Gotti's shit list for all the trouble the tapes of his heroin operation brought. It was the primary reason for the conflict with Castellano, which ultimately led to them taking Paul out.
Once Gotti took over as Boss he made Frank DeCicco his Underboss and Joe N. Gallo stayed on as Consigliere. Then DeCicco was killed in the car bomb and was replaced by Joe Armone. Sammy Gravano briefly became Acting Boss while Gotti was in jail. Later he replaced Gallo as Consigliere and Frank Locascio became Acting Underboss when Armone was indicted. And then when Armone went away, Locascio became Underboss. Later Gravano and Locascio switched positions.
Ruggiero never rose above Captain before he died.
