In most revegetation strategies I can think of, fall planting is the least desirable. These factors will draw from the plant rather than support it. In a regular lot in town, or with water for first few months, all year planting is no problem as long as you plant each section at the same time. You do not want to keep digging holes and watering in plantings you've already done. We've been zinged a couple times with fall planting because the plants go into winter growing instead of hardening off.
Winter planting in a cold winter climate can be very risky.
It takes a few weeks for the plants to harden off, the plants do not have this time if you plant in the winter. If the plants are dormant or allowed to harden off, i.e., being grown in an equally cold climate, winter planting is easy. Do not worry unless your area gets below 15 deg. This climate separates the gardeners from the pretenders.