BTB - Stacking of Magic Saves

How should multiple skills/equipment all granting magic saves be handled? Would magic saves normally stack or must it be explicitly mentioned? Magic saves are not covered by official Mordheim as far as I know so this is a grey area.

In our BTB campaign there are four ways that magic saves can be granted - Dragon Scale Armour, a Leader with a Mark of Arkhar and Daemon Soul mutation (from MIM Corrupted Characters article) as well as Libre Chaotica for a Leader with a Mark of Arkhar. Combining these saves is not explained anywhere that I can see, except a Leader with the Mark of Arkhar gets his/her save reduced to a 2+ with the Libre Chaotica (but it doesn't say how the Dragon Scale Armour fits in).

Here are the quoted rules...

Quote :

Dragon Scale Armour
The Dragon Scale Armour grants its wearer a 4+ armour save that cannot be negated below 6+. In addition, any spell targeting the wearer fails on a roll of 4+ on a D6 (for spells like Silver Arrows of Arha roll only once instead of for each arrow). The armour does not hinder its wearer from casting spells or rituals of his own.

Quote :

Liber Chaotica
This mighty tome of Chaos magic contains all the rituals of Tchar, Onogal, Shornaal and Chaos Undivided (Chaos Rituals). A spellcaster in possession of this book is able to use all spells from his dedicated list. Note that he must still learn a spell twice (ie. spend two skills) to permanently reduce its Difficulty.
A non-spellcaster may choose one random spell determined before the battle from the Rituals of Chaos Undivided. The warrior may attempt to cast it as if he was a spellcaster.
A leader with the Mark of Arkhar increases his save against magic to 2+ and becomes immune to the effects from all Chaos rituals (including Rituals of Hashut).

Quote :

Mark of Arkhar the Dog
Leader: The Hero is subject to frenzy from now on. In addition, any spell that targets the Hero fails on a roll of 4+.

Quote :

Daemon Soul
A daemon lives within the mutant’s soul. This gives him a 4+ save against the effects of spells or prayers.
Cost: 20 gold crowns

I do not like the idea of stacking magic saves (unless specifically stated). There are critical hits which can totally negate armour saves even when armour saves are stacked but there is nothing that can negate magic saves. This can make magic saves quite powerful and perhaps too powerful if they stack.

Personally, I'd like to be able to say that magic saves do not stack (unless specifically stated) and that warriors only get a single magic save roll. This would mean that if a warrior has both the Daemon Soul (4+ magic save) and Dragon Scale Armour (4+ magic save) then that warrior would only get a single 4+ magic save roll.

What are your thoughts? How do you handle magic saves?

I'd be inclined to say they don't stack. Just use the best save out of the ones you have.

Random crazy alternative idea: Grant a reroll on a failed magic save if the model has 2 saves? Just threw that one in there for brainstorming purposes.