By removing "the" and the object of comparison, you have changed the meaning of the sentence.How about, "Sudanese women are most ill-treated.."?
Though "best-behaved" is better in this particular case, you could use "most well-behaved" but not "best well-behaved". It's about having the largest amount of a quality (good behavior), not about doing it the best.
Suppose there is a dog show and all dogs are well-behaved so to speak; then? 'Best' can be used.By removing "the" and the object of comparison, you have changed the meaning of the sentence.