Star Wars Campaign: turn 2 pre-battle rolls. Ready for battle

Turn 2, pre-battle phase.

Reinforcements for the turn. Imperial 6, Rebel 11.

Imperial rolled:
    2 equipment cards
    1 crew card

    5 more fighters (-1 from reassignment)
Admiral roll: 2 successes.
    - Reinforce Fleet, 1 Nebulon B "Cobra"
    - Consolidate Sector 4 with 1 fighter

Rebel rolled:
    2 equipment cards
    1 crew card
    2 gun cards
    3 more Corvette (Corellian Corvette “Corona”, Corellian Corvette "Asahi", Corellian Corvette “Kirin”)

    10 more fighters
Admiral roll: 4 successes.
    - Reinforce Fleet - 1 more equipment card
    - Consolidate Sector 4 - 2 more spaceships from fleet "Kronenbourg" and "Corona"
    - Move Fleet to Sector 3
    - Consolidate Sector 3 - 2 fighters

Update on Consolidate table (I don't use reserve, so I updated it)

Roll	Area	Consolidation	Effect
1	1	Fighter reassignment	1 fighter transfered from fleet to area
2	2	Fighter reassignment	2 fighter deployed in area
3	3	Spaceship reassignment	1 spaceship transferred from fleet to area
4	4	Spaceship reassignment	2 spaceship deployed in area
5	5	Logistic hub	2 figthers and 4 containers deployed in area
6	Convoy	Upgrade	Roll fleet table and assign to 1 area.  Any Card will apply to a battle station

Imperial fleet in Sector 3 denies the battle and take the hyperspace route to attack the planet in Sector 4.

Rebel fleet in Sector 4 is sandwiched. Main Imperial fleet remains idle. What is its plan?

Sector 1: Rebel withdraws
Sector 2: Engagement
Sector 3: Imperial withdraws
Sector 4: Engagement
Sector 5: Engagement, Rebel will be boosted by local garrison.