[mentando]

With the ~3 times of thrust from the Raptor engines, do you think they will move to a "Falcon-3" design with 3 Raptor engines?

Because that would decrease the redundancy, right? With Falcon-9 you would lose 2/9 of thrust if you turn off the mirrored engine in the best case. In a Falcon-3 scenario, you would lose at least 1/3 for middle engine failure or 2/3 for a side engine failure.

[peeters]

Interesting question. I really don't know what their plan would be, but it's worth noting that even with the Merlins, they land with only one of nine Merlins at its lowest thrust. And even then, it delivers more thrust than its weight, meaning it can't hover. That's why landings are so difficult for them. They have to fire the engine at the exact right time, or else they'll just blast off again (or land too hard).

The numbers I could find said minimum thrust of Merlin is 360 kN. The stat sheet for Raptor showed minimum thrust of 20%, which works out to 610 kN. So with a single engine at minimum thrust, they'd need to either come in even harder than the Falcon 9 currently does, or find a new method of propulsive landing.

More relevant to your question, a 3 engine configuration doesn't allow firing a single engine because there'd be no middle engine like the Falcon 9 has. You'd need at least 4 to have symmetry and a centre engine.