But it's not just about the agreements, is it fair, that some small country beats on CT some big countries in first/second match and all the others fighting for the top has easy match as the team has already broken his enthusiasm?
They can do it and it's fair. I don't think small country manager will say to the opponent "Hey, we could beat you only if we CT, but then we can't do anything else in the tourney, so I will just play TIE to make it easy for you".
Example from real life: Soccer, Euro qualifications. Serbia played against us for 2nd place. We already lost any chance to qualify. If we win, Estonia qualifies. If Serbia wins, they qualify.
We fought and won, and Estonia qualified. Do you think Serbians looked at us and said "Hey, you crunched on us with nothing to win!"? No, they didn't. They knew they should play harder and that's it.
To your example: Will you ask your opponent for a deal if you know I can play my match on deal? Or won't you do nothing just not to do it unfair for me?
I will never be in a such situation because even if I am a NT manager one day, I will never make any deals. I know I will be underdog against NTs who are making deals, but hey...competition is about winning on court and not in deals.