Gao Yi flashed into the room, and the three people there didn't pay him particular attention, but they were not entirely indifferent to his presence.
There were reasons why he believed these three were experts.
First, the positions in which the three sat were very particular; they were arranged in a '品' shape with distances exceeding three meters between them. When their boss was in the room earlier, the three had their protected target surrounded in the middle. Anyone approaching would have to pass by one of them or between two of them.
Next, all three had thick necks.
It was not the thickness that comes with being overweight, but relative to their builds, their necks seemed somewhat thick.
Their neck muscles were very developed, which is the foundation of a strong resistance to blows—in other words, a sign of someone able to fight.