Combining interpretations

You asked

How do historians combine several interpretations?

Example

Historian A

Economic crisis caused the French Revolution.

Historian B

Political ideas caused it.

Historian C

State financial collapse caused it.

A later historian may argue

Economic crisis created widespread hardship, Enlightenment ideas shaped political demands, and fiscal collapse weakened the monarchy. Together these factors explain the Revolution better than any single cause.

This is not simply choosing one interpretation.

It synthesizes several into a broader explanation.