If I had to choose a pick where I think HearthArena was wrong, it's pick #4. Quality 4 drops are generally plentiful, while quality 3 drops are generall scarce. This was a huge common knowledge during classic and naxx, then GvG hit and there was a huge influx awesome 3 drops and everyone was like whoa maybe you can pass on good 3 drops sometimes, but now with TgT out and fewer GvG cards in the mix (it biases towards TgT instead of bias towards GvG now) getting enough turn 3 plays can be an issue.
By pick 4 you already have a solid 4 drop, and you have Arcane Intellect, which helps fulfill the "outvalue their hand" role that Polymorph shares space on. Picking up a turn 3 play for fear you don't see many more turn 3 play in the next 26 seems like priority to me. (It's actually even slightly exacerbated by your turn 4 play wanting a target)
The way things panned out, you did indeed get starved for turn 3 plays, so much so that later on Heartharena was pushing the value of Raging Worgen up to huge amounts, desperate for you to at least get that incredibly mediocre turn 3 play into your deck.
Most of its picks were pretty correct. You had to play Master Swordsmith, that always sucks.