Why are guys attracted to lesbians? How to put this simply...
1+1=2.
Mid damage spells: Fireball and Lightning bolt are V's weakest damage spells at this point. Scorching Ray is cheaper and deals more to 1 person, but you have to split the damage between targets to affect multiple people, and Magic Missile does that with weaker damage, no attack roll, and a lower level slot. Orb of Fire/Ice/Elec/Acid/Force/Sonic Deal lots of damage to one target with no SR. What are you trying to kill, and who is casting it?