Why is the same template sold by different authors on themeforest?

Question

CMS

I found the same template (well, maybe each author has them tailored for different CMS, I don’t know).
Here are the links:
https://themeforest.net/item/progressive-multipurp...
https://themeforest.net/item/progressive-multipurp...
https://themeforest.net/item/progressive-multipurp.. How can one template be sold by
different authors? And is it even possible to find out who the real author of the template is?
The question arose after we set the task to audit one site. When checking, I found out that this template was used.

Answer 1

They wrote everything correctly - these are just different versions for different needs and CMS. Without problems, you can sell it this way by agreement with the author of the original.
One author made the template itself, others suggested (or he asked) to make templates for a specific CMS for ease of installation, which the original author did not know how (or did not want to). On the template page itself (this is the initial author), right under the preview there are links to all available versions for different CMS and this already indicates that everything is fine. The dates of the posted products also show that they were made after the publication of the original HTML template.

Answer 2

I will assume that the original HTML template was integrated by other companies into the CMS that they know best.
And part of the income goes to the author of the design.

Answer 3

html, wordpress and drupal - i.e. templates for cms based on the html template were made by different people.
there is also this template for joomla and magento.
see what cms your project is using. if none of the above, then the html-template was used.