- Not only you are right, but also he is right.
Can I change it to the following?
- Not only you but also he is right.
Both examples in the original post are grammatically correct. I find the first example to be easier to understand.
An idiomatic phrasing is as follows:
- You're both right.
Example 3 is not as formal as either of the original post's examples. The following version is just as formal as the original post's examples:
- You are both right.
In the Southern dialect of American English, the following two versions are acceptable. However, they are not Standard Written English, so they are less formal than any of the first four examples:
Y'all are right.
Y'all are both right.