After some experience (50 years) hunting in Germany my two Pfennige worth:
That Sauer video was taken under very unusual conditions, most likely in a game park where pigs are fed all year round. The hunter’s stand is also unusual, near ideal, seldom found in most hunting here. It does NOT show usual German driven boar hunting conditions! It is only meant to advertise the qualities? of a new Sauer bolt action to impress inexperienced newbies.
Usually firepower is unimportant, it is the first shot that really counts. Much more important is some training, shooting at running boar targets with your hunting rifle offhand or a visit to a shooting cinema. In most such hunting here you are quite lucky to get a second shot as a pack of boar crosses a narrow, about 10m wide gap in the woods. So a four shot capacity of your repeater is ample. Favorite rifles for such hunting (by hunters who can afford them) are double rifles and double rifle drillings (a double rifle with an additional shot barrel, a fox or hare may appear any time). An usual “poor man’s” substitute is a common drilling loaded with a Brenneke slug in the left shot barrel. This too gives the opportunity of a fast right(really under)-left at the short ranges usually involved. But you may also use a bolt-, lever- or pump action, provided the rifle fits you like a glove. Action most often is very fast, giving you less than five seconds after noticing the game for raising your gun, take the safety off, aim and fire. Autoloaders are used by some also, but legally limited to a three shot capacity here in Germany. As most autoloaders are rather slow to reload after 3 shots, so I deem them superfluous. Myself, I use either my old hammer double rifle in .500-450#1 BPE, my 7x57R dr drilling or an old Mannlicher-Schoenauer, either 9.5x57 or 8x60S, for such hunts. Even with a double rifle it is rare to get a second aimed shot. From my repeaters I never fired more than three shots in a row. In my experience a running boar covers about five meters at full speed between shots when I use a double, less than 10m if I use a repeater.