As attacker is the left sieg tower useless. The archers can shot you in the back, if you climb it up. You have to redesign the siege tower or let him docking on a wall, where archers can't shoot you in the back. I have possibilities come into the castle, after B and A is taken. I just miss one more on the right side. There is just one ladder to climb, which archers can easy defend. I think a tunnel or double doors would be to much, but some other solution would be nice.
Like the idea with tower in the middle for the archers. Is something different to other maps which I know in other games.
As defender I see a lot possibilties to defend the castle. Just on B sometimes it's hard to defend, if attackers are already there. They can easy kill you, if you jump down and falter. It would better to have a little bit more faster and easier way to come down.
After F is taken by defenders, I have never seen a game, there the defenders could held G. 100% of all match up this point attackers won here. The way from the respawn point of the attackers to G is to easy. Also the attackers can come from different sides, where the defenders can build up a tactic againts this. It's ends up that defenders run to G and try to kill some many attackers as possible, before they die. I would prefere to put the flag more to the back walls and just let some ways to reach here, so that defenders have the chance to defend it.