No, it won't. That's why I call it exploitive. The setup above will only change once the first line collapses.But doesn't the enemy unit placement change during the next days, adapting to the new situation? This exploit will give an advantage only during these few days, right?
The engine does only re-arrange units that are outside the regular combat frontage, and even then, as you noted, you will have an advantage because it takes a few days to rearrange those.