Email Performance Report clicks shows the total number of leads who has clicked any link in that email. This count is independent of any links and how many times a lead has clicked any link on that email.
Email Link Performance shows the number of unique people who clicked each link. It shows the number of leads who clicked that particular link. The same lead could’ve clicked another link. So in the total it would be counted as 2 leads in the report but in reality both are same leads.
This is the reason why you see Email Link Performance report shows more clicks compared to clicks in the Email Performance Report