[Freakish]

It's a product of your low level and mobs level compared to yours. When you play at low levels the range of monsters giving decent exp is small, typically 4-5 levels and anything lower is green. As you get higher this range expands and when you try to land spells on the lower range it is much more likely to succeed. At lvl 60 you would run into the exact same problem trying to root something lvl 58. It might land but it would be unreliable without malo and tash.