Hi writers,

I recently finish the first draft of my first ever book (yay...kinda) but I feel like my main characters are a bit flat compared to similar books I've been reading.

It's a middle-grade book, first of a series (hopefully), and the MCs are twin detectives. I'm tossing around the idea of cutting one twin out completely and just having one much more developed MC.

I'm happy with my plot but cutting one twin will mean I'll have to alter large chunks which is why I am hesitating.

So my questions are:
Do you have any experience with cutting major characters after your story has been written? In hindsight was it a good/bad decision?