Dawn of War Codex

Does anyone else think it's weird that seer councils don't have wraithsight?

A little bit. Although if we are being strict with fluff, I don't think Warlock and Farseer should be granting of wraithsight since their role is entirely different to Spirit Seers.

In terms of balance though, if Seer Council did grant wraithsight, that would be more of a indirect nerf than a buff to Wraithguards since Wraithguards have more would access to being stunned.

If Seer Council had lower models but maintained the same/similar hp, it could be looked at I guess (still not ideal.)

Currently, I don't think it is needed it that was what you were alluding to.

We could make it so that the Seercouncil has one special die last model, which gives wraithsight

No, die last model is a terrible idea for multiple reasons.
Damage spreading, hooking abilities, etc.

Fair enough^^