Wait? What? You “guess“ you will hand paint them?
Okay, please take this in the spirit it is being offered - some friendly advice from someone who’s done this awhile; but if you plan to make it in this business, or at least make a living, one of the most critical, if not most critical, things you have to do is get a firm grip on your processes and the components of any job you undertake BEFORE you submit a bid. Without doing so, there is no way you can accurately predict your numbers. And as everyone here will tell you, the trim, windows, and doors on any interior job almost always take more time than doing lids and walls - sometimes way more.
Don’t guess, plan it out in advance and work everything out so you will know as much as you possibly can on how you will go about doing a job (ex. the sequencing that you are asking about is an important component). And if what the GC is planning to do is going to cause more headaches than it’s worth, or you don’t feel comfortable at your current experience level in taking it on, then walk away. You don’t indicate how big a job this is, but it seems to be substantial, and if you take it on without having covered your bases - and your ass, you may well lose said ass in the process.
Again, not trying to come across as a dick ( it’s been known to happen) but just as someone who’s been there - done that, and learned some expensive lessons along the way.