There is a LOT of technology sharing that occurs across different brands in large companies. R&D research and testing (as well as consumer research) is expensive and time consuming so when you develop a good formula you want to find as many homes for it as possible.
Look at the first 5 ingredients in any given products. If they’re the same the products may very well be using the same base technology. (Of course that’s just a rough rule of thumb but you get the idea.)
If you have any specific products you’d like us to compare just post a link to the ingredient lists.