Is science plan and royal canin good food for adult cats?

i have 3 cats a chincilla 8years old who had an entorotony 2 years ago. and 2 persians 11 years and 4 years old . i just learned that purina is not good for them as the chincilla started having hairloss,and the other two top brands that we get here are the science plan and the royal canin.are my cats save with these?thanks