If you give the birds enough room to get out of each others way you will have less problems. I don't know how this would translate for a split coop like the one in the picture. But this is on wire cages where you don't have to worry about litter. What is strange is that if you pack the birds in this tight you have better production because there is less aggression and lower mortality. If you give the birds plenty of room they develop the pecking order and the lower rank birds are stressed out all the time and don't lay as well.
Egg production drops under aviary conditions.
You will need some shade over the wire run. I've heard the same thing as you - leghorns become less aggressive when packed like sardines and get nasty when they can establish a territory. Yes the coop is mobile and would be moved daily or every couple of days. It has good information about minimum space requirements and recommended poultry keeping practices. The Five Freedoms Freedom from hunger and thirst Freedom from discomfort Freedom from pain, injury or disease Freedom to express normal behaviour Freedom from fear and stress Good luck with your new flock.