Bataille Empire

When a unit retreats after combat and passes around a support unit 3/4 UD behind. The attacker advances 1UD. What happens if he contacts the support unit?
1 the support falls back to 1 UD
2 the attacker must position himself 1 UD
3 resolve combat

We’ve been playing that the supporting defender retires 1UD

hi,

the attackers can't stay and must fall back to be at 1UD from the support unit.

Just a question : how it's possible for the attacking unit to contacts the support unit after an 1 MU advance.

ATT
DEF (1 UD depth)
SUPPORT ( at minimum 1 UD from the ATT as the Defending unit must have 1 UD Depth at minima)

And remember that if a defending unit retreat or flee, if the support unit is closer than 1 UD from the rear of the defending unit , the support unit become Disordered

Regards
Olivier M