Not every class used to be very strong to tank on, but throughout years of updates and feedback every class became fully capable of tanking with their own playstyles and quirks, from the crux generation of Arcanists to the stationary HoT stacking of templar. There were a variety of different ways that these classes played but usually a class skill that provided Major Resolve became a critical skill in that class' playstyle, such as the crux generation of Cruxweaver Armor, or the corpse creation of Bone Armor. Overall this was very fun for variety in how to build and approach tanking in PvE with many different options, but subclassing has changed things and introduced some redundancy for Major Resolve.
The Problem:
In the frequent instances where a tank is providing group support with Expansive Frost Cloak, trying to spec into a class' specialized survivability toolkit is less enticing because of Major Resolve redundancies.
For example, a very strong option for a trials main tank is a combination of Winter's Embrace, Earthen Heart, and Soldier of Apocrypha. This setup provides the ever-useful groupwide Major Resolve, Minor Brutality, great healing, great shields, great sustain, etc. It's exactly what a tank would want from this new subclassing system. However, if I were running this and wanted to use Runespite Ward and Runeguard of Still Waters as my main survivability toolset, which I enjoyed very much on my Arcanist tank before subclassing, then it would be mostly inadequate without Cruxweaver Armor, which was a really helpful skill to synergize with and outright enable that playstyle. Yet, since I'm already using Frost Cloak for the group, it becomes harder to justify slotting another Major Resolve skill just for that playstyle, when I can save bar space for more utility skills by doing something else that isn't reliant on a nearly redundant class skill to keep me alive. This friction comes up a lot for the classes for whom their survivability skills tie in with their class Major Resolve skill for a unique playstyle, with Arcanist, Necromancer, and Templar being the primary examples.
Some suggestions:

• Make class Major Resolve skills provide more value outside of their armor buff, since Major Resolve is much easier to acquire in the subclassing system, reducing the opportunity cost of running multiple Resolve skills.
• Decouple Major Resolve and class "playstyle skills", either by moving Resolve elsewhere or dividing by morphs, such that someone could spec into a unique class playstyle without a Major Resolve redundancy holding them back.

To conclude, I think that the work that was put into making every class tank in a unique way made for fun variety, and while that is still in a sense available, there is unnecessary conflict and redundancy with particular regards to Major Resolve, in such a way that tanks who are running Frost Cloak are discouraged from building into the more unique class playstyles without it feeling wasteful. Providing incentive for these "engine skills" would do a lot to introduce variety in tank builds and choices in a positive manner, and help to resolve the issue, pun intended.
What do you guys think? Any suggestions?