Can two custom templates be used to create a single page?

No, you would not use two page-templates on a single page.

Yes, you can have a different admin-page layout / configuration for different page-templates.

Page-template-A could have two post-editors and page-template-B (or post-format for that matter) could have only a name, email, and featured-image.

You could use a single page template and separate includes to help organize your code.

<?php
// Template Name: 289812
?>
<div class="page-tpl-289812">
    <?php get_template_part( 'filename_foo' ); ?>
    <?php get_template_part( 'filename_bar' ); ?>
</div>

Add filename_foo and filename_bar to your theme. filename_foo outputs one editor-section and filename_bar outputs the other.

There are many ways to add additional custom input to the admin-side of anything in WordPress which I won’t discuss here.