I think the main problem with constitution is armor being so much more useful than health. Most of the time when armor is down you are instantly dead. But what if 20% of all damage bypassed armor? So that every attack deals 80% armor damage and 20% health damage. That'd both make health more useful and cc harder to apply since it'd be harder to break armor.
I wrote about this earlier. Some percentage of damage should pierce armor, giving some percentage of chance to apply a status. Current system must be reworked for sure. Armor, resistances, vitality, dodging, damage estimation - everything. It is not hard in terms of coding, it is a bigger challenge to do the math and balance all this in a proper way.
