If the verb agrees with subject and object and there are confix-forms such as s-V-s-o, then there are s-V-o forms as well.
Standardized
Whenever the verb agrees with subject and object, IF there are confix forms such as s-V-s-o, THEN there is also non-confixal subject agreement in the order s-V-o.
Keywords
verb agreement, subject, direct object, person, affix-order, prefix, suffix, confix
One counterexample! And how many examples for which the implication is true?