The methods used by police in this example are typical of those used by people who have very little grappling experience – holding wrists and pressing down on the head without controlling the body. Two police hold the man who has been arrested for possession of a knife in a public place, while a crowd gathers which becomes a safety concern for the officers. Although the methods used are not causing harm (the suspect is lying on his side rather than face down, most of the officer’s weight is on his own feet and the knee is pressed into the head rather than neck), the knee on the head resembles the George Floyd incident which could quickly incite the crowd to intervene.
It is very likely the man was actively resisting and attempting to escape custody before this video clip starts, however it would not make sense to continue once he saw that a crowd had gathered and was filming. Playing the victim only makes sense, whether it is right or wrong. This video resulted in the police officer being suspended.
Matt Serra, shown in the second video restraining a man who had just threatened restaurant staff and attempted to punch him, sits in the mount position which has the man immobilised. Serra controls the wrists only to prevent him from grabbing and hitting, not as the primary method of control. It also allows the man to breathe and causes very little discomfort.
On foot, walking down an open road with no cover, no concealment, in a tight group, surrounded by terrain which could easily conceal enemy from any direction. This is how you march on parade, not move through an active warzone.