Oh, I think as soon as the Brutes were introduced, Isengard AI was quite good, and even before I always had some difficulty against them more than in recent time Misty Mountains and Angmar because of their already good ressources.

My comment is not such a big deal though, because if we recruit units that can attack the mines at distance (axe throwers and spear throwers), it is not that bad as trying to destroy them in melee, I would prefer personnally only 2 mines in the script because it would be less unfair if we try indeed to destroy them in melee, while still posing a great threat whatever, but that's OK if it stays the same.

Isengard AI in the new update is slightly too difficult. It was already a good opponent in the precedent versions, now this AI is just too ridiculous.
The worse thing are the code which make them send 3 mines in the walls everytime. Those explosive mines are sometimes very hard to see and they may even be invisible and stuck in the wall so that we have to blindly move the cursos inside the wall to see when its come to red and that's bullshit because the Berserkers always enlight them easily.

Would it be possible only to reduce the number of these mines to 2 instead of 3 ? And if possible make them drop the mine before the hit the wall ?

We just released a hotfix for patch 4.8.4. It includes a handful of changes to address pressing issues such as severe lags with Theodred's new abilities or incorrect halfcastles for Imladris.

General

• Added missing textures for Warg lairs
• Haradrim lairs now correctly drop treasure chests upon destruction

Rohan

• Theodred's Attack Post no longer causes lag
• Theodred's Attack Post: Only soldiers from the Muster are now selectable
• Theodred's Attack Post: Soldier commandset fixed

Isengard

• Now always unlocks military upgrades correctly

Imladris

• Walls of half-castles fixed
• AI can now recruit Dunedain more reliably

Dwarves

• Missing textures for vineyards added
• Aldron's voice lines are no longer audible to all players
• Hotkeys for dwarf statues fixed
• Quiet Accords can now be placed anywhere without a minimum distance requirement