I remember someone telling me "never wake a sleeping baby for the sake of a "X hourly feed", but never put your life or a siblings life on hold because of the fear of waking them"
I have a friend with a 10y, a 7yo & a NB... the newborn gets woken all the time, because the baby just has to fit around the older children's needs & honestly the Mum says this is her easiest baby yet... I think because she's so busy with the family lifestyle (they are a busy family) she quite simply just relaxes and enjoys the baby.
What I'm trying to say is waking or not waking a sleeping baby isn't about what books or people advise, it's about what makes for the least stressed Mum & the happiest Mum... where Mum is feeling more relaxed it's pretty much the best thing for the baby. If waking the baby keeps the routine in a place that keeps you comfortable then it IS the most important thing to do... you aren't following a set of instructions to build a house, you are on a journey building a relationship with a fellow human being, one who picks up on your energy. If your energy is stressed then try to do something to help it, as (from experience of a Mum who had anxiety & PPD) it never gets "easier" when you find the perfect routine, it gets easier when you can find the willingness to embrace the journey with its hurdles & zig zags.
Do what you think is right for you, not what a book says & if it doesn't come off, that doesn't mean you aren't doing it right, it just means that you are in a human relationship that has compromises & is constantly evolving.