In the first clause, forbearance is set against ignorance; in the second, the family is praised through a further image of extraordinary remedial power. The speaker does more than assert that the addressees are patient: their forbearance is given an effect, followed by another connected praise.
The two diseases create parallel fields of meaning. The point is not merely that a word meaning “heal” recurs, but that the subsequent judgment grows out of the earlier rhetorical conception.
Branching can coexist with simile in a single passage because the figures describe different aspects of its construction.