The guy played 4 years for REAL, has 100 matches in Champions League and Europa League combined. He's coming in as a free transfer, with a relatively low salary (Imagine calling 750K a low salary for PAOK 10 years ago). He's exactly the type of player that could come to Greece and excel. He was a great player for REAL, but he was very injury prone, and then he was competing with MArcelo for a job....good luck with that. It was all down hill after that. He went to Sporting on loan, and then took a pay cut to go to Rio Ave. All in all, I don't have any HUGE expectations, but will not be surprised if he finds a new confidence in Greece. With Giannoulis on the squad, and Vieirinha on deck come December, I think it's fairly low risk high reward scenario.
Interesting article with some good info on the player: https://bleacherreport.com/articles/2793704-real-madrid-transfer-news-fabio-coentrao-speaks-after-blancos-exit
Also here is a page with multiple articles on the player from the past year....including the time he pulled down Samaras shorts during a match for not helping him up off the ground:
https://en.as.com/tag/fabio_coentrao/a/