Happy Runner 123: I get so pissed when I hear shoe industry people claim that a heel to toe drop (such as the 10mm in the Tarther) somehow helps you avoid straining your Achiles. There is no evidence to support this!! If anything there is evidence that suggests that altering your normal gait and landing encourages such injury and weakens your achiles!!
Right. I interpret this kind of thing as acute vs. chronic, short term vs. long, magic pill vs. holism.
Someone used to standard bulky high heeled 21st century trainers no doubt does put more strain on his Achilles running hard in low-heeled flats, in the short term. But continuing in those high heels run after run, year after year, never allows those calf muscles to stretch, strengthen, acclimate - it's like never taking off a cast.
Similarly if you were suddenly assigned to run a marathon tomorrow, your best move today is to take the day off... but for a marathon six months from now, it's the opposite: you want to get in about as much training as you can between now and then.