Nouns as anagrinds?

I'm new at this setting business and I want to learn, so when my fourth effort was ready I asked for a test solve. The tester pointed out four instances where I'd used nouns as anagrinds and suggested that I use nounal phrases instead. I redid one of those four clues entirely for other reasons. The other three were easy to change and I did so. The original version of one of the four was: "Waste management can create hard work." That was easily changed to: "Management of waste can create hard work." I think it's still a good clue that way, but I prefer the original. My thinking is that so long as the anagram involves only one word, the nounal anagrind makes for a fair clue. If I'd been trying to clue "sweatshop," I would not have used "hops waste management," but because it's just one word, I think "waste management" works fine for "sweat." I hope someone will point out what I'm missing.