Sometimes it's hard to tell which decks will work in arena or not. If I'd drafted those decks, I'd expect them to do above average for sure, though. I'd probably expect even slightly higher than 7-3 from myself on those, but there's so much RNG that you just never know. I've had 12 wins with decks like those and 1 win with decks like those.
I'm really hoping that the recent announcement where they are splitting off ranked play into wild and standard will push all of the netdeckers into standard, so that people who want to make creative decks can play in wild. The ladder seems to be getting more and more stagnant and unimaginative. Last season was the first in at least six months that I didn't make it to rank 5 for the golden epic, because I just wasn't motivated to slog through all of the boring netdeckers to get there. I'm not sure if it will work out that way or not, but with Blizzard seeming to promote standard over wild based on their (extremely flawed) new business model, I'm hopeful.