system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] Why do the Valar have such poor track record with the Istari (wizards)?

Couldn't they have picked better choices. Saruman became evil, Radagast is preoccupied/useless, and the blue wizards are missing in action. Why did only 1 out of 5 stick to the plan? Shouldn't the Valar be wise enough to send competent Istari?
gpt
The Blue Wizards were not useless. The two of them massively weakened Sauron's forces in the east. Without their influence his army would have crushed everyone under an endless parade of elephants.

Radagast was vital in the war effort, on both sides. He helped Saruman capture Gandalf and search for the ring with his birds and animals, and helped free Gandalf. Unfortunately for him the corruption of Saruman notably weakened his usefulness.

So, they had a good track record, but the sudden corruption of Saruman threw two of them into chaos and weakness.