Softimage to Unity Legacy problem.

Hello.
I have been making animated game content for unity. I wasnt having any problems until now.
i have a plotted tank with all it’s animations set.
with the rig set to generic, the animations play correctly.
with the rig set to legacy, the tank does weird deformations.
what i am doing:

  1. rig tank
  2. make shadow rig
  3. select shadow rig and tank geometry and bake (fit plotted values to Fcurve)
  4. remove constraints
  5. export fbx

Does the rig HAVE to be in legacy in unity? its working fine with generic.

20859-leg.jpg

let me get this straight.
Legacy is for mec i.e. bipedal humanoid characters?
Generic is for anything else?
Can i use generic for game animations for tank?