I was revising the chapters and realized that I didn't make something clear, so let me explain to avoid future confusion.
After Cell fought the Saiyans and escaped, he took days to reach Zuko planet and ask the info, so what you will see about the z fighters it's during the time cell took to get the gete star.
My bad if i wrote it as if it was happening at the same time.
If you have questions ask anytime!