Bank Sales Manager: Unstable Job and Income?

Working as a bank sales manager and handling customers' accounts and solving problems and issues for them is a huge challenge. They sometimes have very tricky requests that could take a long time to settle. On top on this, one would have to look for new business for the bank as well. This is done either thru recommending new products/services to existing customers or bringing totally new to the bank customers in.
Both ways, it is a challenge and it gets stressful at times. There are staff who leave the bank after a short spell, citing stress as the main push factor. More often than not, the sales staff have to manage high sales targets set for them by senior management on the one hand, and manage customers' expectations on the other, while maintaining low or zero complaint rates. Harmony among selfish colleagues and overworked admin staff is also hard to maintain.
How to do all these when one has to work fast and furious in order to achieve the high and demanding sales targets?
Some say it is almost impossible. Well, they are quite right. Few manage to weather thru this cycle unscathed. And some bankers who are good at their work manage to earn a very fat salary. However, having said that, these high-earning bankers are in the minority. Probably out of 20, 1 would make it big. Another 5 would be above average performers who are being treated as cash cows, while the other 14 would not even survive more than a year.