Definitely not overkill.
"over-filtration" is an oxymoron.
Unless your fish are fighting a rapid vortex the entire time, you should be fine.
Plus the more live rock, plants, corals, decor, etc. you have, the more it restricts the flow.
I run a 304 and a Marineland HOT Magnum on my 55 gal
and still have low flow areas.