Dual Displays

If you had 2 180 gallon tanks, would you run them through a single sump system or keep them separate? Running them through one sump increases the total water volume through one sump which is supposed to make it easier to keep things the way they should be. On the flip side, keeping them as two separate systems allows you to move things from one system to the other in case something happens. So, which way would you run them, and, why would you choose that option?

Thank you in advance for any and all thoughts on this.