I'm happy I could entertain you on a boring offseason Saturday night!
I try not to comp players. I know why scouts do it, to give a broad indication of what kind of player a prospect is, but fans tend to take comps to heart a little too much. Take Swanson for example, getting comp'd to Derek Jeter. Yes, ideally he's that "type" of player, no dominant tool but above average in everything with high make-up and leadership potential. Some fans hear that and go SWANSON IS THE NEXT DEREK JETER. That's not going to happen or ever will happen.
Can you comp Acuna to Andruw? Sure, above average defense, power. But I don't like the comp because no one will stand up to being compared to the greatest defensive centerfielder of all time.
If I comp, I try to what kind of player they could be if they hit maybe their midpoint career trajectory.
Let's take Allard for example. When I make my lists, I try to think about what a player's ceiling and floor are. (Note on floors: every player has the exact same true floor suffering some sort of injury or disability that prevent them from playing in the majors. That's a given, and also not useful. So when I say "floor", I'm assuming they will be healthy enough to continue to play, they just aren't able to come close to maximizing the tools that evaluators think they have,.)
So roughly, I think Allard has a floor of a dependable but otherwise unremarkable middle reliever that barring injury should still allow him to have a long major league career due to pitching with his left arm. Let's set his floor at "Brian Duensing".
At his ceiling, the flashes of plus curveball, plus change-up, and plus control all manifest themselves nearly every start. His fastball plays up because of it, and he gets more movement on it as well. Let's call Allard's ceiling "Ron Guidry".
So Allard is number 5 on my list, because I think his career will likely fall somewhere between Duensing's and Guidry's. That's a very valuable major league pitcher. Let's call the midpoint comp "Scott McGregor". McGregor was a key member of several Orioles rotations that made the playoffs, and a 13 year major league career mostly as a starter. If a time traveler came to me and told me that Kolby Allard would have more or less Scott McGregor's career, I would go "Hmm, not as good as I hoped, but still pretty good."
Note that neither of these comps are Braves, and neither are Hall of Famers. Braves fans have a horrible time comparing every prospect that comes up through the organization with a Brave of yesteryear. Not every lefty with a good change-up is Glavine, not every righty with control is Maddux, and not every outfielder with right-handed power is Andruw Jones. And when I comp, the floor is just as important as the ceiling.
So here are my boring comps for Acuna, Soroka, and Allard:
Acuna: Eric Davis
Soroka: Alex Cobb
Allard: Scott McGregor