That's pretty true, although I don't know if I could differentiate between high phosphate levels vs low alkalinity, etc.
Mr_X turns his water over so regularly he doesn't risk much going wrong very fast. That's the ultimate in simplicity and hard to argue with. I don't do nearly as many water exchanges and have tanks packed solid with corals, so I go the other way with testing and dosing. Both ways work fine.
don't worry about calcium levels much and use a high calcium salt mix. I have seen acros grow at calcium levels of 350 to 600ppm. Much after that and you create a calcium snow storm. I concentrate on alkalinity, salinity and phosphate. Even PH doesn't bother me as long as it fluctuates over a long time scale.