It's a good idea. It will give you enough water movement to avoid dead spots in the tank. In a fish only tank you would be able to get buy with just the XP-3. But due to the wood and plants in our tanks it's very hard to get that movement with just the XP-3.
But I really have to question your ideas here. In a planted tank you basically only need mechanical filtration. The plants should and will provide the biological filter. What kind of "main" filtration are you talking about?