Warriors are awesome in arena. You can obviously get dicked on weapons, but you just need to draft around it. Don't take upgrade if you don't have an arcanite reaper yet, etc. You don't HAVE to have weapons to do well though, as there are plenty of other shenanigans to pull with raging worgen/amani berserker and whirlwind/inner rage/cruel taskmaster. You can steal plenty of games from people with a single worgen. Warsong commander and korkron elite are traps and you usually don't want them; weaponsmith and frothing berserker are strictly better. shield block/slam and charge are mostly awful, but most of the rest of the spells are passable to awesome (mortal/heroic strike, cleave, etc). With warrior you're basically playing for a big midgame finish, ideally before turn 8, as their late game finish can be a bit rough unless you pull a bunch of insane shit like x3 arcanite/gorehowl/grom.
I also like to stack up on acolyte of pain and cultmaster for warriors as they are both generally superior card draw to battle rage. Cult master is such a huge monster I'd likely take him over almost any other pick. The ability to dump him out on turn 4-6 and trade away 2-3 minions is just retarded. Acolyte of pain is pretty cute with cruel taskmaster too for a decent trade and a couple cards.
If you do draft decent for weapons, especially arcanite reapers, don't be a pussy with them. Kill chillwind yetis, brewmasters, tazdingos, whatever, your health isn't super important as you're pretty likely to be boned if the game goes late anyway. Only thing to really watch out for is enemy life total, as you can certainly reach a point where just stabbing them is better (reaper in play, another in hand, enemy at 15 life etc).
Lastly, you want owls. Probably all of them you can get, as your removal isn't great, and they are close to your only access to silence, which you're gonna really want when people hide behind lord of the arena at 7 health. Obviously spellbreakers to0 (it's probably the best generic creature, or at least real close to it).