If you want to prevent players from interfering, just force them to pass. There are various ways to do this, like discarding cards in the first round.
Nah, everyone doesn’t care. Even if you discard cards, opponents see in you only easy win and 2 crowns. For 10 games, NOBODY passed in the second round in SEASONAL mode.
So what about other contracts, like "win game with 50+ power unit", "scorch unit with 50+ power", "10/10" etc? I'm pretty sure that your opp won't let you build 50+, or control 10/10. Or any other special situation, that needed for complete contract.
As for me: completing this kind of contracts is not about farming reward points (reward for this contract is 1 rp (that equal 50 ore or half of a keg). Thats not serious), it's about playing with friends with a fun deck and finishing one of this.
Ofc, you could say, that achievments should not be easy to get. But some achievments I could get when just playing (activate X Y times, play X games, win with X Y times etc). For this contracts I should build the special deck, draw cards for combo, my opponent shoudn't do something wrong (kill or discard you key-cards, bleed me at r2 etc) and after this you should win the match. Too many conditions for 1 rp.
P.S. English is not my native language, so please be kind to my mistakes.