Mistakidis is actually a winger and second striker - so essentially, he's Pereyra. We bought him last year from Freiburg (he played for their reserves) and loaned him out to Pierikos. Seems he spent his youth squad years in various German teams, and is from Salonica. I've liked what I've seen so far.
Esp since we haven't seen anything for Pozoglou.
As far as Rat...didn't he miss much of preseason due to his involvement with his national team? Or, Tudor isn't as fond of him/doesn't think he has the pace to work as a wingback (something I was wondering about last year). I did see Korovesis play a few times as well, perhaps they're just trying to test out the new players more so than the guy they know is our best LB?
Skondras, seems to me to be perfect for that role. Konstantinidis and Kitsiou, same deal. All fast, aggressive, etc. Our weakness is definitely not on RB/RWB.