I'm sure you'll know from other siblings, it's not an exact science and set routines are a westernised thing that in some ways goes against nature and natural routines. The most natural thing for a baby to do is wake and feed and sleep next to a mother and other family members, but culturally we don't do that. So temperament comes into play, also things like pre teething pain, emotional connection, gastrointestinal differences etc. Some babies just seem to be more sensitive to the world and need reassuring in light sleep cycles and wake, others not so much. The day routine could influence night sleep, but more in an overturned baby being unsettled at the start of the night rather than night waking a 2 or 3 am. My eldest was a good day sleeper by 7 or 8months, but had night waking right up until nearly 3yo... His sleep improved when he stopped daycare and I was home FT with a new baby... In hindsight it may well have been he was uncertain I was there for him and so it was 'trust waking' to check or it could have been fluid in his ears that we found he had at age 5.
So while it could be routine, it's also possible it's 10 other things.
At the point you are now I'd try shortening one of the naps so the second wakeup is around 2pm and then give a 20 min catnap at around 4.30pm then a 7pm bedtime.
