Did you just not read the posts above yours? ;p
Magic resist DOES NOT apply against Miscast wounds.
The Wizard can use his regular 4+ ward save and that is all.
As for the unit, against spell wounds not from miscasts or instant death spells, would be 5+ for rank and file, 2+ for the character with the 4+ ward save.
You never use another model's basic ward save through magic resistance. Only Magic Resistance saves can increase another save, not the other way around.