There are too many problems with the theory that gateway disruption is made with wards...

1. There is no evidence at all for this ward. I have no problem with a bit of insight. Someone once suggested using a gateway as a weapon and in KoD it suddenly appeared. Still, it's theoretical at best, whereas gateway blocking is an established weave and hints that gateway interference is done in such a way.

2. Tactically, a ward is stupid. If you block the area off against Travelling you injure your own abilities too. You cannot escape, or Travel somewhere, or send your own troops off. It's like making a ward against channeling - its helps you but also harms you. In effect, the defending army is pinned down.

3. The warding would have to be enormous to have a big enough effect. Shannow suggests that it's too difficult for a channeler to run around blocking gateway formation and that a channeler can merely make a gateway half a mile away. However, a ward needed to cover such an area anyway would require an enormous amount of the Power - either with a sa'angreal or a large circle.

So in my opinion it works like this...

Channelers ward the battlefield for miles around with wards that detect saidin or saidar. This is an established tactic used by Forsaken generals, especially Sammael who was a master of defense and probably Rahvin who located Rand almost instantly with lightning. It also seems to be a tactic that both Rand and Taim agree to be the most apt for defending a battleground.

When channelers detect saidin or saidar, they immediately Travel to that area of the battlefield. They know the area, so it's easy. A gateway will probably be established by then but no one is going to use one gateway to send an army - more will follow. A group of channelers will then attempt to either unravel the formed gateway, block gateways which are forming, or kill soldiers who are trying to get through. Does this mean that channelers spend all their time running around doing this? Of course it does. If you have a thousand channelers in your army, you should dedicate at least twenty percent to running around trying to thwart incoming gateways and tactical advancements. The other 80% can fight or Heal, or whatever else they do.

Channelers on both sides will attempt to do the following...
- form gateways for reinforcements
- help maintain the gateways in case enemies try to unravel them
- block incoming gateways
- destroy anyone who tries to get through
- try and destroy the channelers on the other side, or at least shield them.
- try and unravel their platforms if they use skimming.

It makes much more sense for an army to do this than to create a Travelling deadzone that hurts your army as much as the enemy's.