The biggest issue for towed guns still isn't rotation or traverse. It is that gun crews cannot push the gun backwards. In CM they will always rotate the gun 180 degrees first, then push it forward.
That means you will not be able to fire from the edge of cover (say the top of a ridge) and then save the gun before it is spotted. It won't just pull or push the gun back, they will rotate it 180 degrees, only then start moving.
That wouldn't be so bad if towed gun rotation was realistically fast, but CM makes it very slow. In reality the crews of small and medium guns has been sized specifically so that they can indeed lift the carriage and rotate the gun on its wheels. At jogging speed.
There also was a similar problem with unrealistic rotation requirement, and then with unrealistically slow rotation speed about vehicle hookup or unhook. Details escape me right now.