Again, that is not a balance issue, that is a matter of combat encounter location. If you are a wizard and get the drop on a fighter 120+ ft away, you'll be able to cast multiple spells before he can reach you with a melee weapon. If it's a ranged fighter, such as with a bow or javelin, it still isn't going to be balanced since spells normally do more damage than ranged physical attacks and they normally have greater range. This scenario isn't a balance issue, its a strategy issue; line of sight, using your surroundings, etc. If the melee fighter gets the jump on the wizard in close melee range, might be lights out for the wizard. It swings both ways depending on each particular encounter.