[Cohen]

Magic Duel was bugged because often a S1 mage could kill an S6 mage, probably getting killed himself but it could be a good exchange unless your 1S mage has also many other paths.
What I think is strange is that this goes only vs Astral mages ... I'd believe Magic Duel should go against every mage, and Astral Mages are advantaged.

Yes I mean flames from sky, murdering winter, seeking arrows, flames from afar, beckoning and such.
Devils usually aren't a big problem if you have Air Magic, otherwise they could be painful even for SCs.
For Soul Slay you've to get prepared... Rune Smashers and Spell Focus, a Banner of Northern Star and if you can boots of quickness and starshine skullcap (but usually you don't have so many gems to forge all those stuff, and especially to give to frail mages ... but in a game with a no clam rule I had that eq for many astrologers).

And of the "standard SC equipment" are you really able to have for each base SC like a Banelord a Starshine Cap that costs 10 Pearls, and you lose the +1S, and obtain only +2 MR ... and have you too the Amulet of Antimagic? Or perhaps you'll need some elemental res? (Banelord fixed eq: Jade Armor, Boots of Fly, Pendant of Luck - this not so fixed but this always work against every opponent... - Drain Life Weapon and eventual shield or 2nd weapon. So you've 1 Misc 1 Head slottage free).
You can kill too a MR 25 guy (Banelord with Lead Shield, AMA and Starshine Skullcap, suited to survive to Ryleh Starspawns ... he died meanwhile the lobo mindless guards held it at bay) even if you'll need your time to accomplish that.

About playing in 8 in world map isn't very balanced.
There're Nations that have better access to long run strat, like Atlantis for Clams.