Proof of Funds, Earnest Money, and Assignment Timing

I will be using the 25 to 1 strategy through my real estate agent. I have no money of my own to use as a deposit. I understand from reading other posts that I can stretch my earnest money deposit window out to 72 hours after acceptance of the offer. I also understand that I can write the contract to give myself the same amount of time to deliver POF (which I do not and will not have - my assignees are going to have it.)

My question is this: if I only have 72 hours to get the contract assigned before I have to provide EM and POF (which I don't have, therefore making the deal fall apart), how are my cash buyers supposed to have enough time to look at the property and do their due diligence? Last time they looked at a property they took more than 72 hours.