You backed yourself in a corner by trying to make a point on the assumption that the save failed and ignoring that the majority of the spells also alter the environment that may, albeit may not, still limit options. So, you believe that all spells should have an immediate impact. They do not, therefore "broken". Looking through your posts...the developer did a poor job, and the game is bad. Why exactly are you so active here then?
Using 1-4 rather than 1-20 does significantly reduce the possible range and would put more emphasizes on bonuses from other sources. Care to explain why that is bizarre and broken?