I can separate my answer to two sections
Recommended:
A bit about the translation plugins
Nothing wrong if you use Polylang, WPML or QTranslate or other, those plugins are widely used and are for that purpose, also actively maintained. Also, those plguins support Arabic language very well.
Switching posts
Plugins like Polylang, WPML and other can translate your posts without worrying about links and updating links everytime you add new posts. So the language switcher that is included within those plugins works perfectly fine and can switch the posts/pages of different languages, all you have to do is to place it somewhere on your site, it’s mostly like widget, shortcode, etc.
Not recommended:
Another option is to setup WordPress Multisite, this is native WordPress feature and maintain all the links manually.
Consider this example
Let’s say you have 5 languages on your site and 25 posts as well as pages, so if you do that manually, you will have manage the links manually for switching between 5*25 posts.