I think the same, because it's the first event of this type you'll see more random deck than any latter event of this type.
It's also due to the fact that not all peoples can get 5 SR (or R) to level max (or effective levels).


Personally I've choose the Moe deck (4 Moe + 1 Sexy) because the last event gave me 60 lvls for my Runa Kamiwano.
Her with both Kasumi and Hiyori Katagiri (who are some of the best Moe) give me a pretty good start.
I've choose to use a Sexy in attack because I have Chikusa Uno level 98 who is the best Sexy (for now). With that she can beat all the other Sexys and all the Babes, she is not good with Moe but the one I'll attack will be a Sexy deck or his counter version (5 Sexy or 3 Sexy and 2 Babe).
My last card will be a Moe in offense (because they don't need to be high level to be effective), and a Sexy in defence (because the one who will attack me will be, most of the time, a Babe deck).

The reason that you'll win a lot more in attack than in defence is because you can choose your target (of course) but also because you can reroll the assist card you've got from your friends. Most of the randomness of the fight will be due to this 2 helps card (the one you get from your friends and the one your adversary get from his).

All of this is cool, but it's all theoretical. When the event will be out we will know to what extent the other players have build decks and what is the most efficient.
For me, I play for fun so if my deck is efficient it's all cool and nice, but if it's not perfect, I don't mind. (well, if it's really really poor I'll mind it ).