I don't know. I can see some of your points, MMD, but I thought that GF2 completed the storyline. Michael had lost his family and consigned himself to hell in this world and the next. So I thought that GF3 was just unnecessary. The story was finished.

As far as specifics go I didn't buy Connie getting involved as she did or Vincent coming out of nowhere to lead the family.

"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.