I love the lightest-weight wool shirts, and prefer them for summer hiking now. Yes they smell better but they also regulate heat better, I think, than synthetics. The wool isn't clammy.

I love microweight wool tanks too, but with the heavy sun exposure at places like Grand Canyon, I'd go short-sleeve for sure. Otherwise your shoulders will be red as tomatoes.

My very favorite (after trying a few brands in the microweight) is the Icebreaker Tech T Lite (140 gram).

Smartwool microweight is fine too (way easier to find on sale) but it's true that it gets holes or rips in it. I think it's slightly thicker than the Icebreaker, too.

Patagonia Wool 2 is actually the nicest made of the three (and maybe the coolest/silkiest of the bunch). But I find the Patagonia shirts get smelly after only one wear. Even VERY smelly. This has confounded me; I think they're 100% merino? Maybe not.

You can wear a wool bra underneath, or, a sports bra that doesn't smell. Sometimes I even wear my non-sport tactel nylon bras on hiking trips, because they actually wick moisture really well and they DON'T smell!