It's actually a valid concern on the face of it, but I think it works out okay.
It's reasonable to think that the modifiers will be something like 50% VIT, 30% STR. You can see
this post for an explanation of why, but the tl;dr is that it keeps tank damage around that of a full VIT tank today while also ensuring that Fending accessories are immediately the best choice (ignoring details about parry secondaries for now).
The exact numbers aren't particularly important, but they do let us demonstrate what happens as item levels increase. This chart (i139 is used because there is no i140 equipment in the game) shows the total amount of damage-influencing stats each class receives from all their gear at each item level using the above weights. It assumes the tank is wearing all vitality accessories:
As you can see, the absolute difference ramps up as item levels increase. This gap will only continue to grow as we get new gear in 3.2 and beyond.
However, the absolute difference isn't what matters here; it's the ratio of damage between DPS and tanks that has the potential to cause problems. If a monk goes from doing 150% of a tank's DPS to 200% or 250%, the tank is going to struggle with aggro as time goes on. What we actually see though, is the following:
The ratio of the monk's damage-influencing stats from gear to the warrior's damage-influencing stats from gear actually
decreases as item level increases. This is because vitality increases faster with item level than the primary damage stats:
- An i150 ring has 29 VIT and 31 STR.
- An i190 ring has 40 VIT and 40 STR.
- An i210 ring has 49 VIT and 47 STR.
As long as that ratio stays the same or decreases, having just vitality on Fending accessories does not cause a problem.