It's certainly possible - mine are all adult now but i had them in a routine by 8 weeks.
They were all breast fed on demand. I can't honestly remember the days az it was a long time ago but certainly at night i had to have them in bed by 7.30pm as i was a Corrie addict back then!
With my first, we bathed her every night but it was a chore so we never did that with the others.
I dressed them in day clothes by day and never had sleep suits on them by day.
So, my nighttime routine consisted of changing them into nightwear, clean nappy. One of them i did massage with oils as that was a popular thing once.
Then move to the bedroom (mine were all own room by 8 weeks) and breast feed both sides til they had drained both sides. I probs kept low light and voice too.
I used baby sleeping bags (and i think i would have put that on before the feed)
Then, gently lift to cot and for my eldest 3, i used white noise (i know this is NOT recommended now) for the younger 2, i had a classical music thing that attached to the cot side. I put that on and left.
I only returned if they sounded quite upset (not running back in to any little sound but certainly when it sounded like it was building to a full scream)
I didnt lift them, just went in in dark, didn't speak, just re set the music, stoked away any tears and left again.
I would've repeated that as needed.
One of mine slept through 7.30 til 6am consistantly from 6 weeks!
But he was a big baby who could hold a belly full of milk.
The others i'd go in and lift them for another feed at midnight. And then back down. They'd go through til 6 or 7 on that.
My daytime routine was fixed with morning walk to school, school pick up. Dh worked regular hours.
My babies just fitted in round the others really.
Good luck!
I do recall all mine kind of fell into their own routine by 3 months - they seemed to nap at similar times each day. I just went with it. But maybe that is also because my days were fixed; we fell in step with each other.