The early season gloss is beginning to lose its sheen, I think. Quite a few of the victories they've had have been through sudden good fortune, not from something Arteta dreamed up on the practice ground, and luck like that cannot sustain a club throughout a long strength-sapping season with the all demands the Premier League puts upon you - and when you include cups and other situations like injuries and suspensions etc, it is a long hard slog on any team. Sure, they'll strengthen in January, but as we've seen the transfer window in winter doesn't usually have the promise of decent signings like the summer does - it can be very hit and miss. And Arteta needs a big squad because they seem to get a lot of injuries, at least a lot more than many others.
There's a long long way to go before the season reaches its climax, but I'd rather be in our shoes than theirs.