Will there be any issue while importing?(since all are on localhost)
Yes and no. The content will be fine, as will the posts. Any images uploaded on the other hand will be problematic. This is because it will need to download those images from the original host, which won’t be possible when using a local environment.
Will there be any conflict in page-id?(since all start from the same duplicator backup, their pages will have identical ids)
No, the page IDs would get recreated with new values on import
Will there be conflict arising to page data connected with plugin tables, example, Advanced Custom Fields, Yoast, etc?
Data in custom tables doesn’t get saved in a WXR export. Neither do options, only post related content. You would need to ask the support avenues of the relevant plugins, or try this out for yourself
My recommendation, would be to just create 4 users on a staging site, and avoid using localhost and import/export altogether. This should eliminate the issues.
However, it sounds like you’re trying to do this to solve a problem or requirement that you have not shared. Perhaps if you asked how to solve/fulfil that problem rather than asking about a proposed solution, you would get a more useful answer.