Arranged marriage peeps, why do you prefer partner from same industry?

In arranged marriage, earnings of partner forms major decider while choosing. Ultimately ending up selecting from same or specific industry. Isn't it a more risky option to choose from same industry? Every industry is cyclical in nature. Some cycles are of few years, while some extend for decades. If cycles turn to negative, both partners would be jobless. Classic example of 'Don't put all your eggs in one basket'

What according to you, are the pros and cons of having a partner from same industry?