Have had a few more games of AoH, now, and played a couple of times with the Gauls. At first play thet Gallic battleboard seems to have a lot of easy to use power-ups. It has some more complex stuff, as well, that requires a bit of coordination. Both games I pretty much just blasted through my opponents' centre with mindless force.
I played 5 points of warriors and 1 point of archers (modelled by slingers) against the Carthaginians. In the second turn I destroyed two units, and left the elephant on the edge, with the triple-activation Gaulish Wave. It didn't leave my opponent too much to work with. Gaulish Wave is great for getting three units into melee, but Power of the Ancient Gods is an incredible dice machine. It's expensive (an uncommon + a rare) but with a few other units around can easily bring 10 or 12 dice (including re-rolls) to a melee, and gives you the flexibility to choose Attack or Defence dice. And Gaulish Fury makes your opponent hesitate to close ranks.
I thought managing Fervour might be an issue, but it's actually pretty straightforward. Perseverance gives a choice between getting rid of Fatigue or Fervour, so it makes sense to keep it loaded even if you're not interested in the Fervour, and Tumultus Gallicus can remove all the Fervour from a unit. I thought the cost of a Saga dice is reasonable to keep the Fervour flowing, but you get a free activation for 1 common dice, in any case, so it is effectively free to use.
I also played against a Syracuse Graeculi warband. Although they were better defensively than the Carthaginians, the Gauls still managed to make some pretty impressive holes in their 12-man phalanxes. In this game I dropped my archer/slingers as there are no shooting power-ups on the board and brought in eight more warriors. They didn't do much either because I didn't really need them, so will consider replacing them with eight mounted warriors, just to give myself a bit of range and flexibility.
This is a great warband for people who aren't very good at Saga, so I will be playing it a lot. My impression was that this is the sort of board that the Age of Magic Hordes could have been, and my opponent remarked exactly the same thing.