It's an interesting thought, but it doesn't really prove anything if you don't look at how versatile other teams are in comparison to their defensive rankings. A single data point is not a trend.
There's also a chicken-or-the-egg aspect to it. Guys who are lockdown defenders at their position don't get moved around. Buxton doesn't get moved around. The good version of Correa didn't get moved around. Are they bad defenders because they get moved around, or are they getting moved around because they aren't good enough to lock down a position? That certainly raises questions about your scouting and development practices, but that's a discussion for different thread
Then there's simple roster math. With the expansion of pitching staffs, teams just don't have the position-player depth that they used to be able to have. Back in the day, there was a 25 man roster, a 10 man pitching staff, and no DH. Take away a starting and backup catcher, and you had 13 players to cover 7 spots. Now, with a 26 man roster, a 13 man pitching staff, and a permanent DH spot, you have 11 players to cover 8 spots. Increased versatility is a necessity, and I don't think this gets acknowledged enough