Dansby Swanson spent his first 2 years at Vanderbilt as a Second Baseman (though he missed much of his Freshman year injured), but he's moving to Shortstop this year due to team need. This creates a bit of uncertainty around his draft stock. Scouts rate his defense highly at Second, where he has good first step quickness, good range, plus speed and enough arm. As a Shortstop most of that should transition, but there are questions about his arm on the longer throws from Short. This is different from Bregman who has played a lot of Short effectively, but is viewed as a bit more appropriate to Second in the Pros.
Swanson is 6'1", 190 lbs with Plus speed (maybe better, per some reports), a line drive swing and fringe average power possible (though much of that will be doubles, not Homers). He just turned 21 and last year was named Most Outstanding Player in the College World Series and Second Team All-American. Lauded for his work ethic and team leadership.
As always, I'll start by looking at Swanson's hitting. As previously mentioned he has a swing geared to Line Drives. This should lead him to a higher batting average, but will result in fewer home runs and more doubles. This is fine since the demands Offensively for a Second Baseman are such that the 10 HR one might expect from Swanson would be adequate. If he can handle the change to Shortstop, even better. In the video below (courtesy of Fangraphs), we can see a few of Swanson's swings both in BP and game action. The bat is very fast and he keeps it in the zone for an extended period. What I like about his swing is that it's quiet. He has a small toe tap and some bat wiggle in his load, but nothing is exaggerated or suggests potential timing issues to me.
As I mentioned he's new to Shortstop this year. That's hugely important to to his availability in various points of the First Round. If he can stay at Short, combined with his hit tool and speed, he's similar to Trea Turner last year and probably goes Top 10-ish. If he can't stick at Short, he may be available to team selecting well below the Phillies. Even the best College Second basemen like Chase Utley, Kolten Wong and others tend to get picked in the bottom half of the First Round. Even Todd Frazier, a College Shortstop, fell to late in the First, as he was seen as a Pro Second Baseman (or Third Baseman as it turns out). So this is a very important season for Swanson. I know some are thinking that the Phillies would use him as a Second Baseman anyway, so who cares if he can stay at Short? Well, it shows some flexibility, it would suggest his arm could probably work at Third if needed. Many Second Baseman have very little room for error during development. For example, as good as Utley's bat is, I have a hard time thinking of what would have happened if he was a bad defender at Second. He was a tire fire at Third, he doesn't have the Power for First, he's too slow for Center and who knows if he would have been any good in Left. That's the value in seeing Swanson stick at Short, even if you have no plans on using him there, he has flexibility positionally.
For Swanson I actually could find a Defensive video, as he made ESPN's Top 10 last year. Enjoy.
Someone asked me the other week in the Bregman comments which player I'd draft; Swanson or Bregman. I said Bregman. My reasoning being that I liked his hit tool a little better, but also that he's already shown he can play Short and may be able to stick there in the pros. So you're talking about moving him down the Defensive scale. I'd stand by that, but my opinion would change if Swanson can put in a good season at Short. He has superior speed, a roughly equal hit tool and a higher ceiling Defensively. I'm still not 100% sure I buy into either completely as the best pick, but it will depend on their seasons and who's available.