Double Harvest plays out really similar to regular HotS in the first 5-10 minutes of a game. The effects of Double Harvest are felt the most on higher base counts, when you go deeper into a game.
The 12 worker start is honestly probably much more disruptive to the build orders and the general flow you'd remember from HotS than most iterations of double harvest even come close to being.
Also, you're wildly exaggerating when you say stuff like "each worker is worth 2-3 workers". Just because it's called "double" harvest, does not mean workers mine at double the rate. It's not even remotely close to that.
In general you seem to be making a lot of ridiculous assertions. I don't have any clue what you're saying and why the consequences would have to be what you're suggesting.
I played DH and in the teamliquid DH tournament. In my opinion it plays very similar to HotS. Where it has the potential to diverge the most is on extreme base counts (like 6 bases). But before then, most of your basic timings are recognizable.
Also, afaik, in the DH9 model 16 workers mine pretty much exactly the same rate as 16 workers in current SC2 (HotS and LotV). The difference (20%-ish boost) is on lower saturations. And you don't actually stay on lower saturations for very long in the early and midgame. It only starts making a major difference for your output in multi base scenarios later on.
Charts below show the % boost from dividing your workers optimally between bases. It uses data from an old DH model which isn't relevant anymore.
http://i.imgur.com/n2EMpRT.png
http://i.imgur.com/3pix2o5.png
http://i.imgur.com/vXQxJVu.png
http://i.imgur.com/bp3OQFi.png
http://i.imgur.com/bp3OQFi.png
http://i.imgur.com/1PqWRwM.png
I personally think much more should be changed than just the mining (more specifically: recalibrate macro mechanics). And if they did that, that would certainly screw with every established process, timing and build order you currently recognize.
But the chaos you're claiming would follow when applying DH to current SC2's design, that's just bullshit imo.
I almost guarantee you'd recognize more build orders and timings with DH and 6 worker start, than you'd do with 12 worker start and LotV econ.
