So it's slightly counter-intuitive, but the "additive transitive" phase is actually a property of intransitive verbs - this "verb phase" model comes from John Beames's work A Comparative Grammar of the Modern Aryan Languages of India (Q113330708). There is a regular pattern in Hindustani (and Punjabi and the other northwestern Indic languages) where most intransitive verbs can be made to take additional objects. (The inverse used to be true in Hindustani too, but this feature has been dropped over time - the Punjabi templates I am working on also have the "subtractive" phases which allow intransitive forms of transitives, or even avalent forms of intransitives.) The "basic" phase describes the base form of the verb (intransitive or transitive). The "additive" phases then describe extensions of either type of base. If written out fully, the categories would be:
- verb-basic-intransitive
- verb-basic-transitive
- verb-additive-transitive
- verb-additive-causative
- verb-additive-double-causative
However, since the intransitive phase can only be a "basic" form, there is no need to distinguish this, and likewise causative forms are only "additive" as there are no verbs with a causative base form. Only the transitive extension of intransitives needs to be distinguished from the "base" transitive template. The idea behind these templates is that it is a lot easier to enter the forms for these if broken up into smaller chunks rather than having one massive template with ~200+ fields, especially since not every verb goes up to double causative - the additive-transitive and causative / double-causative template would be used in edit mode to add these forms to existing lexemes. I think it would be fine to switch the order for double causative to causative double, but the others seem like they might cause additional confusion in this context.
If it would be helpful to look at an example of what I mean, गड़ना/گڑنا (L991835) is a fully modeled Hindustani intransitive verb, and on the talk page of that lexeme there is an explanation of how this verb phase information can be used in the context of larger verbal expressions.