It's damn near impossible to lose even at level 3 if you get the right support. Run a solid deck (whatever you want), attack the type that's weak, and make sure your support covers your ass.

Example:

I run a Sexy deck. I attack Babe decks, and I make sure your support is either a strong Moe (the thing you're afraid of) or a moderately strong Babe or better. Even a 5000 will do.

At level 3, the SED for the team is no more than 59,999. So assuming every card is 10-12K each, if you run a solid deck, you will win 3 out of 5.

In my case, I'm afraid of 3 Babe, 2 Moe with Moe support. No big deal. If my support is Babe, then I can only lose two fights because my support will cover one of the three losses.

You can waste time in level 5, but I have over 300 straight victories by making sure that my support counters the weak point. It's only come down to the support maybe five or six times out of over 300 straight matches.