Only the best-performing creatives in a campaign are introduced into the auction, so your own creatives from the same campaign will never compete against one another.
Performance is determined by historical audience engagement, or if a creative is new, LinkedIn will look at similar campaigns and creatives.
We recommend having 4-6 pieces of creative running at a minimum on LinkedIn. If you have 4 pieces of content running and the appropriate budget this means that you will get in front of that client 4-6 times in 48 hours. There are frequency caps on LinkedIn, which means a member can only see the same piece of content once within 48 hours. The average prospect needs to see 8-10 impressions before completing an action or engaging, so the more content you have live the more times they will see your brand and therefore more likely to engage.