Yep, this is Accurate, the Omnitrix can Scan literally every single Alien DNA Species around the Universe and Multiverse, including Saiyans, Namekians and even the Frieza Race.
Oh fuck that's CRAZY. his whole time i'm like "oh shit what's the big twist in this Fictional Animated Hypotethical" ONLY FOR THE TWIST TO BE THAT IT'S REAL!???!?? HOLY CRAP
If Ben Ten transformed into a sayan, he would be practically powerless. Sure, he would likely be stronger amd faster and have better cardio than the average person. But the thing i love most about Son Goku is that his powers and abilities comes not from his DNA or species, but rather his vast knowledge of martial arts and hard training. It would be like that time when he fought a bodyswitcher who got beat up in 2 seconds. Ben would have to spend years of martial arts practice before getting anywhere. Gwen, who is a blackbelt, on the other hand would have a much easier time controlling and learning to use a sayan.
Shoulda called it Primordial Madness. It devolves your mental state over time until you only hVe your base instincts. Speech, thought, and abilities degenerate. And it also fills you with fear and hunger.