If you're buying at auction, then yes, it's hard to turn the aircraft carrier that fast, but also as a lender, I often find that borrowers wait until the last minute to discuss deals with us. Often, we'll provide them with a list of documents we need to get to be cocked and ready, but they will wait until they have a deal under contract to send us what we tell them we're going to need. I would say to all borrowers, do yourself a favor and chat with your loan officer early in the process. Never say "you don't need that document". Give them what they ask for and do it as quickly as possible. Then, when you find the property you want, they can swing into action without delay. I'm not exactly answering your question, but as a lender I know that there are ways to cut the amount of deals lost to financing down dramatically.
I always add a clause to my PSA contracts saying that I have the right to extend the date of closing by 30 days if I put an additional 1% Earnest Money Deposit into escrow. This deposit would be non-refundable, so you only execute this extension if you know you can close on the property, but it tends to take a lot of stress off of you when the bank says they need more time.