You're right, but there is even more to it that makes a T plane redundant for a rocket.
Power isn't delivered smoothly through the 360 rotation of an engine, the power comes in peaks and troughs inline with power and compression cycles, using a T plane creates a longer period without power during rotation giving the tyre a chance to grip. The more cylinders you have the shorter the low power periods are and the more regular the power periods are. The more cylinder the more even the power so a T plane helps mimic the power cycle of an engine with fewer cylinders.
The rotating mass of the engine and drive train also smooth out the peaks and troughs through momentum (think of the old school stationary engines with enormous flyweights, their power delivery would be almost constant through each rotation). As such the rocket doesn't have low low-power periods, but it also doesn't have high high-power periods, without high high-power periods the tyre's friction is under less strain.
Just as the high rotating mass levels out the peaks and troughs, so to would it level out the artificial power trough created by a T plane. The traction at the tyre of a light weight engine with a lot of cylinders would benefit from a T plane (more uneven power cycle), but an engine with a high rotating weight reduces the impact of an uneven power cycle.
Additionally, a high rotating mass also helps by preventing the tyre breaking traction by reducing the height of the peaks. The rotating mass is like an energy accumulator, engine power goes to the wheels but is also used to rotate the engine mass. The higher the rotating mass the lower the peaks, the lower the peaks the less power in the instant meaning less chance of breaking traction. Again, making a T plane a bit redundant.
Confusing? yes. Just remember that we are looking at power in terms of in the instant and over the full cycle of the engine, and there are competing factors in a rocket engine. Maybe this list will clear it up a bit:
- High power peaks break traction, low power troughs help traction. (not an issue with a rocket as high mass reduces high peaks)
- More cylinders give smooth power, fewer give more erratic power within the cycle. (Being 3 cylinder kind of places a rocket in the middle of this range)
- High mass gives smooth power, low mass gives higher peaks (remember, the engine mass is an accumulator absorbing power in the instant to release later when the cycle enters a lower power period). The rocket has high mass, this mass works against the effect of a longer no power period given by a T plane.
This was my Tedtalk, thanks for listening. Questions?
