I definitely agree with that. They are so clumsy and wobbly at first :) I imagine they would be bumping into each other and tumbling off the side of the ramp.
I am new to this chicken owning too, and plan on doing exactly what you said when my hens go broody, have a small coop with small run attached for her raise the chicks. My favorite looks exactly like yours except all one level, the small A frame coop at the end of the run.