The sentence “I saw he” contains asyntactic mistake.
2001, Martin Haspelmath,Language Typology and Language Universals: An International Handbook, page674:
the rules specifying how agglutinative morphemes are combined with each other aremore syntactic than morphological by their nature and thus are closer to rules specifying how word-forms are combined with each other.
Containingmorphemes that are combined in the same order as they would be if they were separatewords e.g.greenfinch
