Most of the battlegrounds can survive a considerable amount of random activity. But SOA is very, very focused ... you need to get up the hill as quickly as possible.
Have a Plan
Coordinating the attack on both sides of the map is important, so it's best to have everyone on the same page right from the start.
Set up teams on the boats. You have time to organize your groups and give basic attack orders while the boats are sailing in.
Designate classes ahead of time. If you want ranged, or melee or any particular group doing something specific, let them know before you enter the match.
Remind everyone about bombs. People just seem to forget that running bombs is a very important part of this game. Keep everyone focused on that.
Anyone who can stealth should be running bombs full time.
Stack Your Tanks
Demolishers kill gates. Opponents kill demolishers. If you run your demolishers at the opponent's position one at at time, they will destroy your tanks.
This means that the first players to get into a tank, especially at the workshops, needs to be patient and wait for the other tanks to come up.
One tank hitting a gate is not a problem for the defense. Three tanks hitting a gate at the same time are almost unstoppable.
Be Smart With Bombs
Ten mounted people with bombs, all charging the same gate, are hard to deal with. On the other hand, people dribbling in one at a time are easy to kill.
Designate teams of bomb runners.
Make sure everyone has a bomb. Get them mounted and all grouped up together.
If you can time the charge to coincide with a tank attack, even better.
In the Yellow Zone
The trip from the yellow gate to the relic room is the hardest part of the battle. The enemy is inside, and arranged to focus fire on your tanks constantly from the gate to the door. Organization is the key ... you need to attack in groups, and in waves. There are many ways to do this, and you will have to adjust to your particular situation, but here is one approach. Assume that every single person on your team has a bomb.
Plate and Healers: send your heavy guys in first, supported by healers. Dead enemies will rez in the graveyard on the east side of the yellow zone, so you want your first team to push over that way and try to camp the gy. That's the reason for the healers ... this group wants to stay in place and block the enemy.
Mounted Bombers: these come in behind the first group and swing out to the side. Some enemy players will go after them, splitting the enemy up. As soon as your players are hit, they should dismount and fight. If they get kills, they should work their way towards the door with their bombs, but kiting enemies out of the middle is the main objective.
Tanks: demolishers come next for a straight run at the door. These do not need to be defended ... or rather, their defense is already in place. The demolisher guns are enough to break the door. Be sure to start firing as soon as you are in range. And rather than try to ram, it may be better for a tank to stop and bomb the door. If enemy players leave the steps to attack the tank, then bomb runners will have an easier time.
Anyone who dies picks up a bomb (and a tank if one is available) - then groups up - and heads back to rush the door. By now you should have most of the enemy engaged on the steps, so the main gate should be mostly clear when your second wave arrives.
The South Grave Yard
This GY is a two way switch: cap it and you rez south next to the bomb pile ... leave it and you rez north near the two workshops. Whether you cap it or not depends on whether you want tanks or not. Tanks take time to drive up to the yellow zone, so the closer the round is to ending, the more you want to be rezzing in the yellow zone.