I think that ligambi probably saw bringing more people into the family as more of a burden than benefit. It seems like he concentrated mostly on the families gambling loansharking operations as a priority and felt like he only wanted people working for him that were specifically gonna help him with that. He seems like the kind of boss that would not want to muddy the waters by making guys just to keep the numbers up, they have to have some sort of use to what he's doing. Scarfo on the other hand because he was involved with everything had to make more guys and recruit more especially for the street tax and the drug dealing and also all the killing and warfare.
It's the "smaller core" theory that has been applied to the Chicago family, for example. Why make guys just to "keep the numbers up?" Especially if the quality isn't there? And if, all other things being equal, the top guys are making the same amount of money?