That’s easily explained though. Your 210% Overpower doesn’t compare to the amount of damage your extra 346 strength added, even without the extra 110% damage. Main stat will beat out every added affix every time.
This is typically what I suggest to people starting out in the Torment difficulties. Get your main stat and health up while maintaining armor and resists, and then work on other affixes. You can fiddle with it more later once you’re going for even higher torment levels, but starting out, you can’t beat main stat.
Typically when starting out too you don’t have the paragon or glyphs to help maximize your damage either. So you’ll be struggling until you do get those, as you’ve clearly shown.