I have a 6 foot long, 24 in wide, 30 in H tank .8 run 6 hydra 32 at 90%. Coral are happy and I get great coverage this way.After thinking about this answer, I'm thinking about some changes to my lighting.
On my 145 gallon, which is (6ft W) x (18in D) x (21in H), I run three Hydra 32s.
I started them at 40% and then over several months, increased them to 100%.
If I understand your point, I'd be better off running those lights at less intensity, becoming a "more light with less power" configuration.