I wouldn't worry to much just now. It takes time to get into a good routine and especially with your little one being 10 weeks you just think you've got into a routine then teething kicks in or solids or something changes it.
I have a 2 and 1 year old. I cant even remember how the new addition affected her routine. I did find to start with that bath times became earlier and everything was organised with milatary precision to allow for smooth bedtimes and then everything started to fit together.
i did have to sit with pen and paper though because I couldn't remember who done what at what times. I found writing both their routines down a good way and how I could join them together
Also, there was things with the eldests routine that changed such as stopping days sleep, nappy off at night. So theres always something to think about.
I've had to do everything myself and it has taken a lot of thought about how to slot things in around them both. Thankfully is worked, even if my eldest ends up in the bath at 2pm to stop her having a daysleep!!!
Once your little one is off his nightfeed then it'll be one less thing to think about and another change of routine
I remember even if it was my eldests lunch time i'd try and wait till my new addition needed a bottle, so we could all be at the table at the same time. I'd get her ready in her seat with lunch then baby for his bottle
The way I looked at things was i couldn't stall feeding for a baby but could a toddler so everything could fit in and slightly change her routine