I disagree on Don Clericuzio having Pippi as his consiglieri.
Pippi is never mentioned as an advisor to the Don, he is much more an opperative captain then a advisor. An even a captain he was not. I always saw Giorgio as the consiglieri to the don. Although he consults with all 4 of them. even Cross and Dante.

Therefore, to my opinion, Don clericuzio was his own consiglieri.

But it depends on what the families goal is. I think that you cannot have a consiglieri that HASNT been operational if you are solely running a crime family. In the case of Don Vito, him having Genco as consiglieri was a much wiser choice then Don Michael having Tom. On the other hand, in the era of Genco, the goal of the Corleone family was much more crime related and therefore needed a street smart consiglieri. Under don Michael, it was much more the goal to get the family into legitamate business, so maybe therefore Tom wasnt such a lousy choise.