Easier to arrange the buildings and build the wall.
It is also good for team games where there could be a border with a straight line pattern and not circular where sometimes they give corners that are difficult to defend.
Their scope was improved, but they have very little resistance to the projectile.
Currently: 20% vs. Ranged with 130 resistance points (Base).
I would give it 40-45% in the late game since the unit is 2 population and very expensive.
Skirmisher has 30% vs. Ranged with 120 resistance points (Base).
One possible way to improve Ottoman troop training: