After some years of driven hunts in Germany (not 50 but 20) there was only one time I've seen a pack of boars which came across like 'on a pearl necklace'. And also only one situation where a very good shooter used that situation and took four boars with five shots in a few seconds. He used the Sauer 202...and was the german master in that shooting discipline.
Most german hunters use bolt action rifles of different types. From Mauser 98 (me...) to the modern Sauer or Blaser. Double rifles or Drillings are in an absolute minority. Under our conditions I think it is better to have five semi fast shots than two very fast ones.
It is like anywhere: you need 'your' rifle and a good training in fast shooting on moving targets. But additional you have to be familar with the game. In that few seconds (like Kuduae explained) you have to identify the right ones...