I would say discuss, discuss and discuss.
My experience with failed and delayed automation says that it is lack of foreseeing what causes all these issues. I don't advocate writing long documents which no one would read but to try to decide in advance on needs of -
Automation components which would be reused all along, and need to developed first.
Automation components which would use those reusable components, as real development of this stage needs to wait till you are not done with step 1.
By and large your approach looks viable to me. Always take some time to review it from time to time.
~ seleniumtests.com