Yup, just get 5 cards of the same type and dont attack unless your support is a type that counters your counter.
For example: You have 5 sexy cards. Moe counters sexy, so you attack only when your support card is babe (that counters moe).
This way there are only 2 ways you can lose:
1. Opponent has SED boosting cards (nothing you can do really)
2. You are extremely unlucky.
Example of being extremely unlucky:
Let's say you have 5 sexy cards and a support babe card. You will attack only babe decks so your opponent must have at least 3 babes. The other cards he has is 1 sexy and 1 moe, and his support is moe. If his sexy card will fight first and will be stronger than your sexy, then your support kicks in but also loses since sexy counters babe. So you lost first fight and don't have support anymore. Then you lose to his moe card. Thats second loss, and normally you should be able to beat all 3 babes but his support is also moe so you lose 1 of these 3 fights which results in 2:3.
But as I said, defender has to be lucky enough to draw moe as a support and most people don't pay attention to where they place their cards so you have to be extremely unlucky to lose like that :P

Altho, keep in mind that if u farm rank 1's, there's a higher chance of finding SED boosters.