I'm confused? We have a one high dps and one low dps composition now? Isn't it just pure rng with a very slight emphasis on trying to have 1 ranged and 1 melee? Healer's have a fairly reasonable chance of being put with like minded DPS particularly at peak, whereas tanks will likely be the same lottery that we see currently. How is it actively going to make things worse?
Do note that I originally made this suggestion during HW when the DPS disparity between top and bottom tier players was significantly bigger than it is now. Your view on it being a waste of dev time is pretty fair now given how heavily gated the current dungeons are. All 3 experts only really have the potential for one properly massive pull each now, so yeah, I'll concede that point.