Itherians in normal realms

I would remove Itherians from the normal encounter pool, at least in normal realms, for the following reasons:

[ul][li]They are supposed to be rare.[/li]
[li]We don’t get any further knowledge from fighting them, which means we get the other creatures’ knowledge more slowly since 2-3 creatures in each fight are normally Itherians.[/li]
[li]It kind of makes no sense for lore reasons, though it’s fine to have that kind of separation between story and gameplay.[/li]
[li]They also make the “contains more itherians” rare sigil property useless.[/li][/ul]