I assume that I don't have to explain to anyone who runs gorge regularly that and why the loot from endbosses like Glacis can be quite ... disappointing, regarding the stats that are rolled on the items. Thats why I did some maths to conclude which stat would drop by which chance when Glacis is killed.
The graphic should be self-explaining, at least I did all in my might to make it this way, since explaining maths in a foreign language isn't that easy for me. 
The rates I will refer to are from the last column "distribution while 3 stats", since this includes the added possibility of a second stat on the weapon.
As it is very obvious to see, the most "unuseful" stats have the highest possibility to drop, while those that are really used have a lower droprate.
Additionally the distribution between the "useful" stats themselves is very different, with sta/sta having the lowest rate by far, though in a raid usually there is approx. the same number of pdps, mdps and tanks+heals, that will roll on respective stats, making it for certain classes way harder to get stats than for others.
Furthermore enhancing plate items with fragments is the least rewarding choice, due to the possible stats on them, but they are the only ones to get sta/sta as well.
Also I think that on Loki in Inferno the distribution of stats on the dropped weapons was different, for example sta/sta and sta/wis did also roll on 2h swords (and 2h hammers?) afaik and str/str and dex/dex did not.
If im correct here, I wonder why this change was made, to the disadvantage of tanks and heals. Please correct me if I'm wrong here at any point, I'll be glad the redo the maths.
One way to solve this "problem" would be to change (back) the possible stats that might be rolled on each weapon, to even out the rates.
I would propose something like this, where sta/sta and sta/wis may be on one more weapon that str/str and dex/dex are on at the moment (2h sword or 2h hammer) :
This change would lead to a very equal distribution of the "useful" stats, while the most "unuseful" stats still have a higher droprate, which I guess is the main problem that is bothering all players, not just tanks and heals.
For this, I would propose an Aldo-like lootsystem for the stats that may be on the earrings, since there always is just one stat on them. If I remember correct at Aldo there only could be str/str, dex/dex, int/int and sta/sta on the items, so it would look like this at Glacis:
It will mix up the distribution of all stats pretty much, but I think in the end something like this would be more in favor to all players than it is right now.
Please comment on these proposals. What do you think of it and do you have any better ideas or can you add any changes or tweaks to them? Try to stay as objective as possible on this and do not look for benefits of your preferred class/es, because my intention is to find the best way for all classes.
Considering the possible implementation of any of this, I do not know if it would make sense to change Glacis' loot already or to wait until a new instance is released.
Also keep in mind that stat-fragments in combination with AC might be added (soon?) to Glacis, like they were to Loki, and that this will affect the availability of all stats as well.
To wrap this up, I tried to keep as much on point as possible, and not to stray into long explanations, but if anything was not made clear enough or is confusing though, please tell me so and I will try to explain further.
By the way, GMs and Developers are of course invited to discuss this and share their point of view on this, since this is a very gamechanging issue, or confirm me in my presumption to begin with. 
Cheers!
