I'm not saying it isn't working out, but I don't think any of those moves were very high-risk. Williams' biggest risk was on Thome, who was injured last season, but he correctly recognized that DHing would keep Thome healthy. Dye was a FA signing who hit according to his career norms last season and is hitting a tick above his norms this year.
But take a look at the guys Williams has acquired in recent seasons:
Most of these guys were either coming off slumps or were character issues with their previous teams. Williams tends to target guys who are high risk/high reward guys and managed to catch lightning in a bottle with these guys last season.
So far, it's working pretty well for them this season.