and all of them do the same thing.
Jump+backpedal+180turn+abuze animations.
Haven't seen Largg enough to comment on his playstyle, but neither Teeth, Strudog or Idzo does a lot of spin-jumps, at least from what I've seen. The usual is just to stab in the air to gather momentum and then drag it down in their face. I only use the jump myself when I use the pike, because you'll glance most of the time if you don't. With a long spear (I.E. in strat battles) you won't see me doing the lolspins. Remove the jump with my pike and I'll quit nerfing myself and use the long spear instead...
It's quite true what you said about the numbers, the amount of very good pikemen/long spearmen is very low compared to great players using greatswords or dueling polearms. That's mostly because GS and long polearms has good support ability with the long stab/overhead while still having 2-3 other great attacking directions. Also, Strudog, you forgot to mention Red_Pike/Oriental. Great pikeman.