I hear you but don't agree.
if i am to allow a user to do GRV's, but not stock take adjustments, they will simply capture the wrong qty in the GRV & then take the stock home.
You might now say, but then the invoice wont balance...
But, they will simply enter the wrong quantity & change the prices so the invoice balances....
There is no substitute for the right stuff!
You don't trust them - don't allow them!