honestly, I dont see here advice from pro-players and I am not pro, but I can adviced to you strategy: first of all you souldnt nervous and play sably, without a haste.
If two players play with each other than better leave them alone, of course if you doesnt have a really good (badass) cards.
if one of the players is offline you have two ways: 1) be passive and to ruin the offline player
2) or be agressive, kick out your rival and taking your advantage of chips x2 take out your opponent's slowly and wait your deserved first place
i hope it will help you!