Which literary term would the white-topped wagons strained and stumbled in their exertions like fat sheep?

The literary term used in the sentence "The white-topped wagons strained and stumbled in their exertions like fat sheep" is simile.

Here's why:

* Simile: A figure of speech that directly compares two unlike things using words like "like" or "as".

In this example, the wagons are being directly compared to "fat sheep" using the word "like". This comparison helps the reader visualize the slow, laborious movement of the wagons.