Here's what I've found in my lure building:
One joint lures, without a bill, move in a wide S pattern. I thought my first one joint lures, which I made to imitate the Garon, were failures because of their wide, slow S swimming action. Little did I know that it is a great lure action. Butch Brown's one joint trout baits are killer!
Two joint lures move with the tail flapping like a flag in the wind. I like these for crappie and bluegill lures, where I burn them on the outside of the weed edge.
Three joint lures moves with a fluid motion. If you make the first/head section twice as long as the other three sections, and keep most of the ballast in that head section, the head will be more stable and the swimming motion will be in the last three sections. Never put ballast in the tail, or it will kill the swimming action, and cause the lure to swim tail down. I use three joints for all of my trout lures, because trout keep their heads still when they swim, unless they're being chased.
More than three joints and the lure slithers. It's actually really cool to watch in the water. Someone here a while back made a snake with lots of joints, and it did move just like a snake.
Hope this helps.