No quick answer to this one. But a good broker will know from experience what information a particular lender is looking for, and will make sure they highlight this information to the lender.
Here's one example - self-employed client. Spent a lot of money on once-off items in a recent trading year, so net profit is down for that year. Broker A might simply get two years audited accounts (minimum requirement) and send them in with no further information. Lender will take an average of the two net profit figures and make an offer.
Broker B might ask the client for four years accounts, because the average of four years net profit will be higher. Broker B might also point out to the lender the fact that the low year's net profit was due to expenditure on the business and not worsening trading conditions, and document same. Lender might then take a higher average net profit figure into account and offer more.
Same client, different figures due to presentation of information.
P.S. - For those not already aware from previous posts, I am a broker.