Yep that is how it works. More STR helps maintain threat easier, plus self-healing skills/cooldowns are scaled to more damage = more HP healed.
However, of course with the STR/VIT debate I would only recommend starting to max out such when a tank can play their job correctly with appropriate cooldown use, isn't under-geared, and can meet a certain HP threshold for the instance. WAR has cooldowns like Thrill, Vengeance, and Raw Intuition easily available to help get "Defiance-like" defense while in Deliverance.
So I always use full STR even in roulette, alex, and Ravana EX. Like I keep a cooldown rotation going from mobs to bosses allowing healers to DPS, or at-least I hope with some DF healers.
Just like how we healers can use CDs like Bene, Dignity, Lustrate as-needed for a big heal burst for DPSing or what not. Using the big stuff like PLD Hallowed Ground early-on as an option to handle a bigger pull helps too to allow a healer stay in clerics longer, and it'll be up again for that instance. So double win. Of course we've all seen bad tanks go out there "saving" the good stuff like Sentinel and HG and end up never using them. That mindset for trivial content is just thinking there is going to be a fail.
