What is a tactic here ?
What I tend to do (Win most games this way) is to have a team of all uncommons and 2 event or fusion cards on the team.
Reason for 2: Higher chance of running into one quicker
Reason not 3: 3 becomes too much and allows bots to have 3 cards in their decks (Making it a higher chance of defeating your event card)
I've been using this since RR first came out and it's been doing very well for me. I tend to only lose if my event cards are at the end of the deck.
As long as I pull one of my event/fusion cards before round 10, I believe, I will most likely win.