The first one has a baroque feeling (perhaps the last part with figures in 6 sound a bit "modern").
The second one sounds more classic to me.
And the third one is more clearly romantic.
So, I don't see the connection between all of them. I think they work very well as separated pieces. This is something I have also done, and finally I "undo". I mean, I have some pieces and I think they can fit well togheter, I rename them to become a Sonata or whatever.... But with time I understand they doesn't work together, simply because they were concevied as separated pieces.
The Prelude in G minor is wonderful. I like more this style than the others.
Another isuue, which is a personal choice, is that when I compose a sonata-allegro or anything like that I don't like to repeat exactly any section. I prefer to make variations always. But this is also because I tend to use others styles (with "dissonances", modality, etc...).
In conclusion, if the three pieces are part of the same opus number, with no evident relation between them, it's OK.
If you fell they are closely connected, it's OK, too. It¡s your choice, of course.
Anyway, I enjoy them.