@Noght
Yes I understand the potential range is greater then 36". I also understand that it is a chariot dragged by a pretty mean monster. Please.
I also do not disagree that the unit is under costed and you will see loads of double IB on the tourney scene. However, unlike you I do not have faith in GW to "fix" IBs through an errata. So I start looking for ways of dealing with them.
The shorter range should allow us to complicate our opponent's decision loop. The more complicated the decisions your opponent has to make, the more likely he is to make a subotimal decision. No one ever plays a perfect game.
Planting our cannons well with in range makes his decision easy. Putting them such that he has to move across/behind his lines, shoot at near max range, delpoy on a weighted flank as you suggest, may lead to a less then optimal delpoyment phase/movement phase/battle plan on his part.
Looking over the Bat Rep, I still feel those shots were extremely long. The OK player either misplayed it or was very lucky (which happens). I also notice what looks like a wall/obstacle (the mortar and War Alter are behind it). Perhaps it would have been better to create a "grand" Battery behind the wall. The first Iron Blaster shot likely would have destroyed the wall but been stopped. The second destroys a cannon. The OK player would have had to accept two cannon shots back. If you could have destroyed one, the other may well have fled off the board (given their starting position and movement rate, they would have been with in 6" of each other).