Fortifications

We are putting on an historical relight romans v Germanic tribes. The Germans are defending on one flank hill treated as broken ground on the other flank difficult.wooded hill and in between about eight units wide are temporary defences with ditch in front treated as narrow strip of broken ground. No problems with the rules on the attacks on hills on flank but struggling a bit with the Roman attack in centre so welcome comments. Romans are a mixture of FP and FL the Germans FP. The romans can attack as a group with the FP being disordered by the ditch i.e. Broken ground
1/ if the Germans decide to man the defences first with a few S units do they do the temporary prevent there loss on contact. We are treating the defences that attackers suffer minus one in Melee and defenders get a plus in cohesion test.
2/ the Germanic FP units are large do they still get the plus one for depth when defending defence works.1.
3/ if Germanic forced back do the romans automatically cross fortifications even if fail to pursue on dice roll.
4/ if romans fail to pursue the large Germanic unit which then moves back do the romans then get the benefit of the defence works or do the Germanics or now nobody?
Thanks eric

1. It looks like fortifications don't stop automatic dispersal of S and Art units so if the S are contacted they are dispersed.

2. Why wouldn't they?

3. An interesting consequence for the change from Us to HBW in movement. In Impetus all units were guaranteed at least 1U of Pursuit and so would get over the fortifications. In Impetus 2 that is not the case. My suspicion is if the Romans don't get any pursuit movement they don't get over the fortifications.

4. I would think the Germans get the benefit of fortifications but not the Romans.