But...I...I don't wanna DPS, I'm a healer...

[Sida]

Tanks with STR gear are a really mixed bag. You get those who look at their HP "ok, i have quite enough of that, let's put the rest to strengh" and use their CDs smartly. There are those who do the same but quite don't grasp the idea of CDs.. then sadly there are those who are "muh deeps", put everything to strength they can and tank in dps stance just because. The latter ones can end up with less HP than a dragoon if there is also a bit of gear disparity and they indeed tend to be rather challenging to heal.

Even then though, as someone said, tank having strength gear doesn't make you heal them more as such as they still take about the same amount of damage. They just don't have that much buffer for it so healer can't let it drop so long, but if you're decidedly not DPSing in the first place that shouldn't be an issue at all because what else would you be doing than healing.