"A fix?" Are you suggesting that a lawyer isn't able to determine a weak case against her. That was the original contention.The fix may be better against the other defendants.
Here's an interesting take. Maybe worthy of consideration.
Sidney Powell is perfectly aware that the case against her is solid. She's equally aware that any conviction of her can't be pardoned. So she is choosing to avoid jail time.
Seems more likely than a grand conspiracy of the justice department that although is weak still induces people to plead guilty.