Given that one does not rise to the level of Don by being ineffective, a Don is effective in many areas, but maybe not all. As I opined in another thread, Tom's effectiveness would have manifested itself in keeping the organization running efficiently. I don't see Tom as a greedy or vengeful person who would use his position to exact unusual tribute from his minions or to eliminate perceived family competition a la Scarfo. Tom was imbued with Vito's principles and would have run his family accordingly.