Document Migration from target environment to source environment

Hi All,

Requirement:

                    I have a use case where I have to get documents from target environment to source environment.

Information:

                    I have list of appian documents id in my source environment database.

Approach:

->  I have developed a web api in target environment , it will return document based on appian document id.

-> I have designed a process model , In which I am getting appian documents id from table and calling target webapi using integration object.

It was working fine and getting documents as i expected.

Inputs required :

Which way is better among below two approaches.

1) Getting appian documents id's as a batches ,using MNI  and pass it to sub process having integration call logic 

2) Looping approach .

I don't have enough information about number of appian documents id's to process , Please share your thoughts 

Thanks 

Aj