If the prefix position is the only possible one for a subject-affix, then the object-affix also occupies this position in all forms (with the exception of Wolio) or at least in some of them (no exceptions).
Standardized
IF in verb agreement with subjects agreement affixes can only be prefixes, THEN in verb agreement with objects agreement affixes are also prefixes in all or at least some verb forms.
The proviso “at least in some of them” allows variation of object-affix position. Thus in Wolio (Austronesian), object-affixes do not always occur in a prefix position which usually occupied by a subject-affix (Kozinsky 1981).