https://www.techradar.com/news/this-is-how-huawei-is-keeping-the-p20-and-mate-10-pro-different

The top-tier Huawei P20 will launch on March 27, just five months after the arrival of the flagship Mate 10 and Mate 10 Pro. It will give the Chinese firm two flagship smartphone ranges, which may be a little confusing.

Huawei isn't the only phone manufacturer that has competing handsets in its own line up though. Just look at Samsung with its Galaxy S and Galaxy Note series, or Sony with its almost revolving door of new flagships on a seemingly half yearly renewal cycle.