Here's the video. The launcher appears a little familiar however I don't believe three engines can work because the central engine is too big for thrust for landing! A boost-back burn is demonstrated.
What criteria do you apply to determine if there is too much thrust to land? I don't know of any theoretical upper limit. Higher minimum thrust and acceleration make landing more difficult, but not impossible.
Theoretically, as thrust goes to infinity, the time needed to reduce the vertical velocity will be zero. In a real-engine, there's a certain minimal time for startup+thrust+shutdown. Particularly, if the turbopump is involved. Therefore, there is, in fact, a maximum practical landing engine thrust given by the dry mass of the stage.
Furthermore, considering that we're likely to be looking at a 100t+ launcher The engine will likely need to be larger than the F-1.
First, F9 can use 3 out of 10 engines. In this case landing on one of three engines is not unusual.
Second, if you want to create an infinite thrust engine you could also imagine one with an infinite start up time. Both are possible. Both of these conditions are relevant.