So... turn it back into what it was before it was buffed, but somehow even weaker?
What would that achieve outside of making it completely irrelevant unit outclassed by Stuart and M15?
Depends on what changes we are talking about.
Its lethality is heavily dependent on being stationary (almost all the damage is in the 50cal...which has 0.375 moving accuracy) and the Canister Shot. Locking away either the Canister shot or some of the DPS behind vet would still leave it with its excellent HP, Speed, and Vision.
Likewise if you go after its survivability, its going to depend on how much is taken away. A Greyhound with canister and 50cal at a Stuart timing is going to be very scary, and not a lot of AT weapons will be on the field at that time. (222 would actually be able to hunt and kill it though, Greyhound only narrowly wins with its current stats)