Sorry for the typo - that should have been Tunze 6015. The aquascaping restricts quite a bit of flow (similar to my 17 gallon Frag tank, which due to the extensive racking requires an MP-40 running at 80% ReefCrest.)
The Tunze 6015 only puts out ~475 GPH and with the dense aquascaping, it creates a gentle, laminar flow around the tank. The MP-10 (200GPH-1574GPH) will run at the lower output will create opposite flow. It seems like a lot, but due to the shape of the tank, design of the aquascaping and the fact that the pumps will be creating opposing flow - I don't think it will end up being overkill <fingers crossed.>
If it doesn't work, I'll just replace the Tunze with the Vortech.