Hi I'm new to Heavensward and was wondering about bonus stats while lvling my DRK

Is it true that all tanks should max out strength on their bonus attributes?

My FC member noted that strength is a must if I want to keep aggro during lvling phases (since you could party up with end game players), but frankly I'm not having any issues regarding aggro at all.
Yet considering Alexander Savages have tight dps checks and there are small advantages like being able to kill mobs and lvl up faster, I was a little convinced.
If I'm not facing aggro issues, would it be okay to raise vit and give healers a breather, or would capping str grant more merits I don't know of yet?