Currently when you post an article on LinkedIn it is connected to your profile and it specifies that you are the author. Pat Reda and I just co-authored and posted an article on LinkedIn. There is currently no provision to share the article among multiple authors and their LinkedIn profiles. This single author implementation for multiple authors is misleading when someone views the article. The only solution is to post it individually from each LinkedIn profile. But then there are multiple copies of the same article out there. Not a satisfactory solution.
Please go to your LinkedIn profile, go to the very bottom of the page to the footer and click on Send Feedback to request that LinkedIn provide the capability to link multiple authors to the same article. The more people that request this feature, the greater the likelihood that they will implement it.