Advanced wooden walls for barbs??

I'm looking for a more advanced sort of wooden walls as an alternative to the stone, large stone, and epic walls for all the barb factions in RTW.

I've searched around a bit here and on other sites, but it's a bit tough to sort through all the info for just this one set of changes.

Is anyone aware of such work already having been accomplished?

What I am looking for is a tougher wooden walls with more defensive towers along the sides. I'm not looking for a massive upgrade, but more of a reasonable upgrade along the lines of what the Gauls accomplished when facing JC prior to Alesia. I figure Alesia was the culmination of Gaulish defensive structures, but their effores there proved they had the capability and the knowledge to heavily fortify their towns/cities and I feel RTW has held them back in this regard.

I know I can easily adjust the hitpoints myself, but I don't think I can just add towers without some more significant level of modding experience and effort, both of which I lack.

If anyone can point out such a modification, even it if is a part of a larger mod, that would be great.