Given the fact that there are 15 different lubricants listed on that chart and the only application for Mercon LV is the TR3160 I think it would make sense to use it.
Where on Tremec's website do you see a recommendation for the TR3160 as used in the GT350 as using Dexron II or VI? You have to be very careful as Tremecs site is typically dated, as are their pdf's, and you have to pay close attention the specific application as well. I suspect you were looking at a GM TR3160 application.