Jose Iglesias finished the 2018 season with a wRC+ of 90, two points better than the entirety of Twins 2B for the season. He's averaged a fWAR of 2.1 and bWAR of 1.7 over the past three seasons.
I'm more on the Iglesias bandwagon than anyone else on this list. If the Twins lose out on him (the only reason they would is he is not the top option on their board), Lowrie seems the next best option, as he brings a far better glove to the party than any of the bats guys listed above at 2B.
This would give the Twins two average-ish defenders up the middle that each flash a wRC+ roughly 15% above average. Either solution seems workable.
The Twins finished 6th in runs scored in the AL in 2018 and 9th in wOBA. The success of the offense will hinge on Sano, Rosario, Polanco and Buxton, not so much on the production of a new middle infielder...unless that middle infielder is Manny Machado of course.