The 84 Twins had good pitching, mostly, but were not yet a good hitting team. It makes sense that they tried to pick up hitters only. One also has to look at this through a contemporary lens. The MLB at this time still had some teams just starting to adopt full-time closers, and the Twins were one of the teams that were late to the party. They really didn't know what they were doing with Davis (or, at least, Billy Gardner didn't). Plus, Griffith was working on selling the team at this time, with the sale being finalized in September, and would not have been focused on trades and may not have been paying attention to what was happening on the field at all. Note that this year's team doesn't have the "We're trying to sell the team" excuse going for them....