Sounds awful if you are completely ignorant about percentages.
If by some strange happenstance you aren't ignorant, you would realize there ain't a lot of difference between Bregman's 97% fielding percentage and an impossible to achieve (for thirdbasemen) 100% fielding percentage. Actually, Clement of Toronto has the highest at .986, which rounds off to 99%. He was just 1 error to Bregman's 5.
Consequently, the only way to "measure" fielding prowess is to look at range, difficulty, etc. They are all important. And that's why Bregman's DWAR is +0.8, which is tied for 3d best among MLB thirdbasemen.
The same thing applies to team defensive stats. Right now the Sox with their 46 errors have an absolutely abysmal fielding percentage of 98%. That's right--go look it up. And the pristine, wonderful fielding percentage of the Rangers is 99%. That's a 1% difference between the best team in MLB and the worst.
So the only want to measure real team fielding prowess is to dig into the details of each and every player. A quick and dirty version of that is to check, position by position, the DWAR's of the Sox players.
Right now Narvaez leads all MLB catchers with a 1.0 DWAR. Ditto Abreu in RF with 0.8. Ditto Rafaela with 1.3 in CF. In LF Duran is treading water at 0.0. Same goes for Story at SS, 0.0. Kristian Campbell is underwater with -0.7. Ditto Casas at 1b, -0.6, also Toro, -0.4, and even Gonzalez, -0.2.
A rough assessment of those Sox DWAR's is that the outfield and catcher are well above average and the infield well below, especially with Bregman out.