the situation with predicted grades & offers

could someone please explain to me the affect of predicted grades on uni offers - so say my dream uni Exeter for econ & pol offer is A*AA-AAB. Does the kid with predicted grades with the lower end of that spectrum get a lower offer or is it the one with higher predicted grades bc surely tutors know that predictions are inflated. I'm asking this bc my predicted grades could be between a*aa-aab
thanks!