How to file H1 Amendment for 2 projects

Hello,

I am currently on a project with client A and my petition has been approved thru them till August 2021.
I am getting another project which I can work on simultaneously for which I will be working remotely for the most part. But the client B is providing letter only until July 2020.

Will filing an amendment for the new client reduce my petition date to July 2020 from August 2021? If that happens what will become of my original H1B petition which is valid till 2021? Can I file an amendment which includes both the clients, even though the Client A was already covered in the original approved petition?

Any information is highly appreciated!

Thanks

I am not sure if you can do that i.e. include two end clients on same petition at same time.

It is possible that the total duration is reduced after amendment approval.