When configured as first image, the problem is that developers do repo init / repo sync by selecting one of slaves.
Since a developer selects the one of slave, it leads not to maintain the load balancing equally between slave 1 to 7 so the request by this developer is to occur to loads to a certain slave. We already dropped the notice to these users who tends to occur to this type of behavior. However it seems they do not actually abide by the rule I recommended.
Therefore, I am thinking to use L4 switch as described the second image. Can you please let me know if you have the case study by using L4 which I consider to have from now?