You think the damane would really overlook soldiers? By your argument, they didn't do any fighting since they came to the wetlands, since you seem to think they only fight channelers. Why do you think that dealing with flows they can't see would freak them out? They have already faced the Asha'man in combat, and done a credible job. It was Rand's superior mobility that was driving the Seanchan back, not any great advantage of channeling. The Seanchan were spread out through the mountains, and he was defeating their forces in detail. Once they realized he did not have a massive force and was using Travelling, the Seanchan adapted and came up with a plan that started costing Rand, and made Bashere want to call it quits. The Seanchan WILL adapt, react & overcome the novelty of such a tactic as they have before, and there is nothing to suggest that Travelling, saidin or linking will present any insurrmountable obstacles to them.

That is not to say these things cannot be useful. When the Seanchan adapted to Rand's mobility by concentrating their forces so Rand would have to attack their superior numbers, they became vulnerable to a single, phenomenally powerful attacker, such as when Rand whipped out Callandor and inflicted on them their greatest defeat not involving undead superheroes. Gareth Bryne could no doubt take advantage of these two weapons. He can concentrate them by using gateways to defeat their dispersed forces in detail, and he can blast their large concentrations with blasts from linked circles that individual damane cannot overcome. The biggest question is whether Egwene will give him his head in such matters.