I don't think you need to justify anything, you know what you need and who are we to judge? Besides, I'm sure you've heard of chicken math? I would bet MOST of us have more than we need, I do. Ours are dual purpose too so it's not like they don't have a reason to be here for one reason or another. I think the feedback you're getting is more about the number of birds for your coop size.I will add pics soon of the yard and shed. We intend on dual purpose birds only. I feel like i want to justify my flock size a little. We have five kids and three adults and we are making the transition to self sufficiency. The plan is to not drop below 15 egg layers and to process and keep the freezer stocked. We are intetested in adding goats before next summer. The shed was an optimistic hope at repurposing an already existing structure and to try to save some bucks, but starting from scratch may be our choice. My husband is a self taught carpenter. He is very capable.
You mentioned using a tarp on the run. Yes! You can use that to block wind and rain and the flock can still roost there. Chickens roost in trees so it's not like they necessarily NEED a coop. That's more about us wanting to protect them at night when predators abound.