They represent ten different teams. Of the ten tournament teams, only three had a top ten HR hitter: Baltimore, Toronto, Chicago Cubs.
In 2015 only 20 players hit at least 30 HR, so the number almost doubled. In 2015 Baltimore also had the player with the most, also 47 HR, but he was Chris Davis, not Mark Trumbo. In 2015 Nelson Cruz was also second.
In 2014 the number of players with at least 30 HR was 11. Nelson Cruz was the only player with at least 40 HR: 40. Cruz was then with Baltimore.
In 2013: 14; Chris Davis 53.
So in the three most recent seasons the number has about doubled twice: 11, 20, 38.
In 2016, teams with multiple 30 HR players:
Baltimore: Trumbo, Davis, Machado
Boston: Ortiz, Betts, Ramirez
Seattle: Cruz, Cano, Kyle Seager
Toronto had the functional equivalent of three: Encarnacion and Donaldson, plus Jose Bautista (Joey Bats) who hit 22 in only 423 at bats (AB); 2010-2015: 54, 43, 27 (332 AB), 28 (452 AB), 35, 40. Bautista was healthy for the 2016 tournament and hit 2 HR in 33 AB.
In 2016 these teams had two 30 HR players: Chicago Cubs, Cleveland, Detroit, Milwaukee, New York Mets (plus Jay Bruce 33: 25 Reds, 8 Mets), Tampa, Texas.
Eleven of the thirty teams had multiple 30 HR players: six teams in top ten in scoring, three in bottom ten.
Seven of the ten tournament teams had multiple 30 HR players: Baltimore, Boston, Toronto, Cubs, Cleveland, Mets, Texas.
No tournament team had only one 30 HR player. These three tournament teams had zero 30 HR players: Giants, Dodgers, Washington.
Both teams in the finals had two 30 HR players:
Cubs: Kris Bryant (39), Anthony Rizzo (32)
Indians: Mike Napoli, Carlos Santana - both 34
Of the top ten in team HR, only St. Louis and Colorado had only one 30 HR player. The rest had multiple.
Of the top ten in team runs scored (Boston most: 878), only Washington did not have a 30 HR player. Six had multiple 30 HR players: Boston (3), Cubs, Cleveland, Seattle (3), Texas, Toronto. Three teams had one: Colorado, St. Louis, Arizona.
Of the ten teams scoring the fewest runs (680 or fewer: Yankees), three had two 30 HR players:
Tampa (Longoria, Brad Miller) 672
Milwaukee (Chris Carter, Braun) 671
Mets (Cespedes, Granderson) 671
Oakland had one: Khris Davis 42. Including the Yankees, none of the other six in the bottom ten had even one 30 HR player.
Bottom line: it sure helps to have multiple 30 HR players but teams need other things.