I have always thought the role was overrated. There are some intelligent, financially savvy or politically connected mobsters ("fixers") who have performed a lot of what we're told a consigliere does but that was because they already had those skill sets and were performing those roles even before their appointment to that role.
With the exception of people who were in actuality the boss in all but name (Accardo) or people who had their own power base (Caponigro) I think most consiglieres, like everyone else in the Family were appointed by and served at the pleasure of the boss.
The boss can do whatever he likes to the consigliere; he's the boss.
"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming
Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.
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