The injury is part of stunty, but I think for the purposes of a B&C the lose of Stunty (and associated Inj penalty) is OK, as
1) They can't be blocked, so the chances of injuring them is limited anyway.
2) They can't pick up or carry the ball, so why worry about the passing range?
3) They're suposed to be high on Drugs/Fungus Brew, so they probably don't feel pain as much as regular gobbos.
Won't comment on the rules, but I love the image of a Longbeard with a Gyro strapped to his back!
I'll have to see i I can find out the old (ie 2nd ed) SW rules I worked out (rocket-propelled skates, Mr. Longbeard? Right this way sir!)
Currently an ex-Blood Bowl coach, most likely to be found dying to Armoured Skeletons in the frozen ruins of Felstad, or bleeding into the arena sands of Rome or burning rubber for Mars' entertainment.