The Naga/Lamia strategy is absolutely brutal, but it does have a _few_ problems... nothing insurmountable, though. The beautiful thing is that the Regeneration is a percentage, I believe, so Gift of Health is an absolute must for these... they regenerate all the damage they typically take every turn...
It's not my favorite strategy, but it's definitely one of those that is rather easy to win with. Any of the auto-generating unit themes (Ashen Empire, Soul Gate, and Carrion Woods) tend to be easy as well.
And don't forget, people, that Lamia Queens are, imo, one of the better conjurable researchers. And they get good paths, and if you are lucky it won't take much to put up Haunted Forest... that puts paid on Ulm at the very least.
Wyatt