

My normal routine is to combine chest back and core into one routine. I alternate that with my leg routine and accessories (mostly arms and shoulders) routine. That lets me hit each twice a week with one day off, but a lot of that is also going to depend on your personal recovery speed.
Since it’s something you would like to focus on I would recommend hitting the area 2-3 times a week if your recovery time allows.
*this is a recommendation from an internet source and should in no way be considered medical advice. Please consult multiple sources and determine appropriately how valid this response is.
It isn’t a terrible recommendation if you have good form and are comfortable with the lift. Deadlift hits pretty much the whole back when it’s done right, but it can also be done wrong in quite a lot of ways.
Even with deadlift, I would probably still add isolation lifts targeting the areas you want to see improvement on.