I got your point and I agree on the intent. But you gentlemen forget one crucial thing.
Next build is a worker, and we cannot allow ourselves to lose food, as the tiimeframe to build the scheduled builds require all food we can get. Remember that we will go to size 1. again at the very turn we hit two, so we will face no rioting.
That very new worker will road up the ivory as its very first task, if you review the Revised Provolution Plan turns 1-30. Which means, that the ivory will be up and running long before we hit size two again.
So please go for irrigating the Wheat and roading as originally planned, elephant is handled by worker two in a heartbeat.