According to fangraphs, the Twins have a number 3, and a bunch of number 4/5/6 types. Also, no one is suggesting they need to have five number 1 starters. Also, you can sign a FA to a long term deal, so that when they are good, that player is still here. If they aren't good in the next 3-4 years, they will have wasted Buxton and Sano.