The answer to your question would be: That depends.
the motivation of the seller,
ability of the seller to sell at the discounted price (many sellers are leveraged out or their equity and can not take a low ball offer because they can not come to the closing with money),
the cleanness of the contract.
If the seller has enough equity or if not, has the ability to bring money to the closing table,
If it is advantageous to the seller to close quickly
If there are no contingencies, or if the contingencies are settled quickly,
The seller may accept a lowerer cash offer than one that a buyer needs to obtain financing.
However, if the cash offer has an average closing date (30 - 45 days, depending on area), and/ or has open ended contingencies, the seller is no better off with a cash offer than with an offer from a pre approved or even just a pre qualified buyer.
best of luck