Personally I agree. I noticed that although there is archie, I rarely feel like it's accurate. I have read that it was quite ineffective back then, but the amount of it was still high in certain areas. That's just me though.
The anti-air artillery was very ineffective at the time but machineguns on the ground were something to be feared at low altitude.
The balloons generally had numerous machineguns on the ground nearby, defending them. I think that was SOP late in the war, at least. There were pilot accounts telling of the crazy amount of MG fire you'd receive when making such low altitude runs on balloons. While a good portion of it may have fallen behind the aircraft due to misjudgement of the lead angle, there was still enough lead flying around to make it quite dangerous. That's my impression from the accounts, anyway.