SLaughterMAster with GS?

My general is a Beast when given: Fencer Blades and Glittering Scales.
But I keep getting told he cant be given Magic armor, is this true that Glittering Scales can't be given to a Slaughtermaster? and i just wont to be fursure on this because this combo is great and i really don't want to stop using it. But rules are rules.

Normally a Wizard cannot take magical armour unless his unit entry stipulates that mundane armour is available to him. Since a slaughtermaster can take an Ironfist, which as a shield, is a piece of mundane armour he is allowed to use glittering scales or whatever other piece you want.
This allowance was not intentional, Jervis and Jeremy simply overlooked that this would happen if they gave the slaughtermaster access to the ironfist. Jervis wrote a nice little paragraph in the FAQ explaining this, also including the laugh inducing phrase to try not to use magic armour as it would break the "spirit of the rule." No one really listens to that on principle

The rule is if a character can take mundane armour then they can take magical armour.

Our Slaughtermaster can take an ironfist AKA shield,  that means he can take magical armour.

Your combo is completely legal and don't let people tell you otherwise.  Our Slaughtermasters can indeed take magical armour even though they are wizards. (normally wizards can't take armour except for Ogres, Vampires and Warriors of Chaos)

It's 100% legal, I use it regularly myself.

As LatteOkapi alluded, Slaughtermasters/Butchers using magic armor is specifically addressed in the Ogre FAQ/Errata and it is legal (albeit frowned upon by fluff). There is no rule-based argument against it.

Note that a Firebelly however still can't use Magic Armour, as he has no access to even an Ironfist. Easy to forget, that.