If you are a citizen you are either a natural born citizen or a naturalized citizen. There is no third category. Rubio and Cruz never became naturalized citizens. So they are either natural born citizens or illegal aliens.
You’re asserting a false dichotomy.
They were Naturalized in 1934, Before they were born. It was a blanket naturalization. It even uses the word "Naturalization" in the law.
You are mistaking the fact that they didn't have to go through a PROCESS as meaning they aren't naturalized. Well, the CHILDREN of Immigrants who acquire American citizenship also don't go through a process. The ADULTS do, but the Children don't. This is called "derivative" citizenship. Their citizenship (which is created by naturalization) is derived from their parent's naturalization.
So the fact that there is no PROCESS is immaterial to the fact that they are NATURALIZED citizens.