Controlling what is controllable is essential; asserting an uniformity through a distinct event is an excess of trust.
The healing of the paralytic does not guarantee that the doctrinal message of the teaching on the mountain is received in an uniform manner; it is an oversimplification.
How can one ignore the noise of the crowd, potentially more impressed by the miracle than by the subtleties of a doctrine?
Thinking that the crowd could have focused on the spectacle of the miracle, like a investment committee distracted by an announcement of exceptional profits, would have diluted the impact of the teaching.
Such an uniformity is a posture that entirely depends on the discipline and perception of the recipients, not a certainty.