Keep in mind that combination schedules are okay. No problem. If there is one feeding a day where your baby needs more time between feedings, you can do 3.5 hours for that feeding and 3 hours for the rest and still get in the correct number of feedings in a day.
You can do a combo 2.5-3 hour schedule. With both of my kids, that schedule also required one 2 hour interval in the evening (they were/are breastfed).
You can do a combo 3-3.5 schedule. I have done a combo 2.5-3.5 hour schedule. Kaitlyn is on a 4 hour schedule right now, but her last feeding comes at 3.5 hours so I can get her in bed in time. I can go on. Create your schedule to serve your baby's needs, your family's needs, and your needs.
So while you are creating your schedule, remember the option of a combination schedule.