Before he took the throne, Finubar the Seafarer, current Phoenix King of the High Elves spent a long time rattling around the Old World. He was the first High Elf to enter Athel Lorren for around 3'000 years.
That's a long old time, even for Elves and only the very very oldest Wood Elves will have ever lived in Ulthuan, or even remember a time when they were something other than Wood Elves.
The Wood Elves received Finubar politely, but with no great love or feeling if kinship. They had no interest in returing to Ulthuan which was, as I say, not even a memory to most of them.
When Finubar returned home and reported the existence of the Wood Elves (all High Elf colonies in the Old World were thought lost after Ulthuan pulled out) Ambassadors were sent. The Ambassadors were greeted, and treated with indifference, occasionally a little hostility.
Elves, no matter where they live are proud and strong-willed. Wood Elves have been doing just fine for three millenia thank-you-very-much and have little love for the Elves of Ulthuan who abandoned them when the Old World got a little too tough.
So yes, both Asur and Asrai are on the side or Good and Order, and both have some goals in common (Niether are fans of Chaos) but they do not regard one another as long lost brothers.
High Elves are very likely more friendly toward Wood Elves than Wood Elves are toward High Elves, but they are both willing to tolerate the other, and niether has any real reason to fight the other.
Looking for a friendly wargaming club on the Isle of Wight? Drop me a line.
Sisters of Battle - The Order of Glory Undimmed - 2'500 Points | High Elves - House Cyredeth - 2'500 Points | Bretonnians - The Muster of Sir Jules Estelle - 3'000 Points