I just realized that all of the Wych's starting weapons are Exotic, and they only have MWT Universal. Can Wyches not actually use any of their starting weapons?
The Kabalite Warrior has a similar problem in that they cannot buy any non-Splinter Weapons with their free acquisition and expect to use them.
It's a problem inherent in Xenos PCs - Xenos weaponry is Exotic as standard, which requires a talent for each individual weapon. Giving them a decent range of starting weapon proficiencies can be tricky, so early and regular access to Exotic Weapon Training talents is necessary (a couple at rank 1 at least, so starting/early characters can pick up unusual weapons).
That said, I'm surprised that Wyches weren't given Exotic Training (Wych-Knife) as standard.
Writing Credits for Fantasy Flight Games: Into the Storm, Edge of the Abyss, Battlefleet Koronus, Hostile Acquisitions, Black Crusade Core Rulebook, First Founding, The Jericho Reach, The Soul Reaver, Only War, The Navis Primer and Ark of Lost Souls