My first try of this mission but i found better strategy

It is important to keep the imperial skirmishers and scouts

1. Patrol the first path with one scout when you will give more scouts and skirmishers, when you collect more units, continue the path near the tower you will give a ram with extra HP, destroy towers with rams (ignore the farm)

IMAGE 1 : https://prnt.sc/mtnqqb

2. An enemy patrol is not far from the last towers, try to keep and scouts when you fight, after enemy killed, ally will join your army and you must continue to destroy a military camp, if you attack, enemy troopers spawn, kill all units in the camp

IMAGE 2 (wave 1 spawn) : https://prnt.sc/mtnw36 IMAGE 3 (wave 2 object in area) (without terrain custom) : https://prnt.sc/mto5xs and Chu Ko Nu have -4 range

3. Continue to the bridge, you need the 2nd ram and return near the base of blue

IMAGE 4 : https://prnt.sc/mtocia

4. Note : walls have extra HP (+10k) but the gate has its weak point, the gate have +10k HP, if an unit open this gate, HP return to normal, with your skirmishers, attack the tower on left side, you will attract the Chu Ko Nu and monk, they will opening the gate (normally i will have kept the door open with some units to let the rams pass rather than destroy it with less HP to save time)

IMAGE 5 : https://prnt.sc/mtooa6

5. Send scout in this area you will control siege workshop and creating rams, (up to capped ram first for more dammage) you and blue will go to Imperial age

IMAGE 6 : https://prnt.sc/mtorgj

6. Destroy the castle and university (the castle near the gate have less HP) and blue must have 0 military units in this area and GG

IMAGE 7 : https://prnt.sc/mtotuz