not so. as solo sorcerers and solo mages, mind blank would be incredibly useful. especially with the amount of mind affecting magics out and about, not to mention that once charmed you're dead in the eyes of the game. mind blank would be invaluable. vanilla 8th had nearly no good spells, save trigger, wilting and incidiary. now with the pro-elements we have 4. arguably ggoi is usable, but its not part of 2.ed afaik atleast. mind blank is. and least of all it should not be kept out of arcane spell selection because something simillar is in the divine.
i've given my suggestion due prosess and might have to reconsider as i think it would make both spells hugely OP. im fairly certain that it should work the way i suggested, but the reality is that it would make the game less enjoyable. it would be little or no way to protect against. and with the AI the way that it is, one would have to re-program SCS2 so the mages there would have the same knowledge as you, else it would be another cheap trick... but as far as theory goes, it should deal crushing/blunt damage as well as elemental..
what is the current ideas for the limited wish and wish spells, if you're in a divulgatory mood