You raised 3 interesting points above I didn't actually think about (or maybe I just didn't think MUCH about
) :
1/ The Ljos could as well go for OO or Runes... and THAT would be bad (as stupid as it may seem, I kept thinking about ancient forests and haven't even thought about this possibility)
2/ The inherent production edge of keeping forests around also applies to military production. The Ljos can actually mass-build offensive units, and that doesn't sound quite right
3/ Arendel Pheadra (or whatever the spelling is), although you didn't name her directly, has a powerful combination of traits, Creative + Spiritual if I remember correctly. If the Ljos are given a chance to found several religions, Spi gets even worse since they can swap religions a lot without losing much until they get their religion-specific units.
I think I'll be running a particular test case this weekend, even sooner if I get a chance, trying to run exactly this strategy: get Arendel, try to rush to OO and Runes, try to get the better of both, and attempt a Drown-rush on the closest neighbour(s). That might be interesting. In fact, I'm not even sure I'll bother getting Gilden Siveric on the way, it's not like I valued him so much. Definetely worth a try.