It depends the way you look at it when comparing Barty and Khromacheva. Obviously they have opposite styles, but overall they are quite similar.
Just think about Federer and Nadal. Completely different games yes. But they both have many similarities, like they hit with lots of spin. Their matches are always about angles they can generate, movement and their skill.
I don't know those other players you mentioned.
About Ash not having enough power, yes she doesn't hit hard. But her technique is perfect and she generates lots of topspin on her shots, so when the ball bounces it gains pace, so her angles can be devastating. Also if she lands the ball deep on the baseline, the awkward bounce she is able to get prevents her opponents from attacking her. Ash is not a counter-puncher, she doesn't like endless rallies or running around, like you said her movement is not good enough for that game-style. If a rally is going too long, she tries to finish off the point.
Also you just leading me on to what I hate about WTA, by aggressor I guess you mean ball-bashing. You don't need to hit hard every shot to be aggressive. Something as simple as creating angles and moving up to the net is also aggressive play. In the WTA players don't have a happy medium, you are either a ballbasher or a pusher. Barty has this style which allows her to get safe margins over the net and use little energy, while also being aggressive.
Thanks, can you provide a direct link to the video?
Edit: I like Bouchard too, like Anett they both seem really friendly.