I have an 8ft tank, I got a pair of maxspect gyre 350's on each end and 3 MP40's along the back wall. Plus L1 return pump running at max 3100gph. I have the Gyres set to max at 60% and the MP40's cycle up to about 80% of available power.
My point here is that you can add all the wavemakers you think you need and you will never have TO MUCH because you can turn them down if you need to not run at 100%. I also love the programs available on the wavemakers I have. I run a Push Pull with the Gyres at 60% for 5 minutes each direction and a High Energy Reef with a 4 hour Nutrient Transport mode over night on my MP40's. My sand bed stays clean and clear of detritus, there is enough water agitation to lift waste into the water column.