Question: I'm considering a metal hip roof for a new build with a rectangular footprint (no valleys) and the wider sides will face north and south.

There doesn't seem to be much of a consensus among home builders on the internet, except perhaps a recommendation for moderately pitched roofs in the range 4/12 (18.43 degrees) to 6/12 (26.57 degrees). Some home builder website suggestions include 15 to 20, 25, or 30 degrees for the best roof pitch to withstand strong winds. Wikipedia (<https://en.wikipedia.org/wiki/Hip_roof>) mentions an angle greater than 35 degrees is necessary for hurricane regions.

Answer: 
0.6° or 1% (1:100 slope) (normally considered "flat" but you need some slope for water to run off) would be "best" for winds (least exposed area to wind pressure) and indeed you'll find plenty of flat concrete roofs in the tropical hurricane belt.

Flat roofs are less than ideal on other considerations - as with most things, you have trade-offs.
I am not an expert but the optimum pitch to minimize uplift (for a single storey dwelling with a hip roof) would likely be around 20 degrees (e.g. <https://link.springer.com/article/10.1007/s40091-019-0227-3> ; <http://web.mit.edu/parmstr/Public/NRCan/CanBldgDigests/cbd068_e.html>). A steeper slope like the 35 degrees suggested in the Wikipedia webpage might be useful in hurricane regions but elsewhere the additional expense may not be justifiable. Also, wind uplift pressure generally increases with angles greater than 45 degrees and with angles smaller than 20 degrees. A flat roof (<10 degrees) would experience the greatest suction effect but as Ecnerwal, Lee Sam and crip659 point out a roof's resistance to being torn off also depends on building materials and other structural factors.