I'd be massively surprised if Vettel and Alonso don't come out on top.
Alonso, agreed. Also not an Ocon fan. Vettel, not sure. Stroll's put in some pretty solid performances this year, whereas Vettel really hasn't. I think it might be pretty even between those two.
Now that you mention it
Raikkonen & Schumacher
Stroll & Vettel
Ocon & Alonso
Although i wouldn't be surprised if Vettel and Alonso were both quicker.