Depends on the difference in flow. Too little and you will get air buildup in siphon tubes which will eventually break siphon. More flow keeps the air bubbles flushed out of the tube. Unless you attach a aqua lifter to the siphon tube. But aqua lifters aren't always reliable.
Better to get a more powerful pump and put a valve on the return line between pump and display tank to throttle the flow back to match the overflow. Fewer working parts this way.
Edit: this is assuming you are using an HOB
overflow and not drilled tank.