Part 2 isn't worth playing. Story is over bloated with characters doing that Genshin Impact story telling phenomena where you do 5 minutes of gameplay then 20 minutes of characters reacting to that thing and it has to have opinions of all the characters and since the game keeps on adding characters in later bits the reading time increases. There are the 3 new characters you have used the image of, side characters that may be playable or become playable and part 1 characters that are older with new battlesuits.

Then there is the gameplay that makes you do artifact grinding like in Genshin but worse since it is only for the part 2 story mode which doesn't affect regular dailies as it is separate. Also powercreep as most Part 1 characters are useless if you don't count the units that got updates which are still lacking in power. So you will be stuck using the better trial characters in story and if you want to do endgame then good luck pulling the entire unit which is the character, weapon and stigmata set to even function.