If subject of transitive verb is expressed by a confix, then at least one of the parts of such a confix (prefixal or/and suffixal) may designate the subject of the intransitive verb as well (without taking into account positional phonetic changes).
Standardized
IF subject agreement with a transitive verb is by means of a confix, THEN the prefixal and/or suffixal part of that confix will be used for subject agreement on intransitive verbs.