That's interesting Fate that many babies fall into one, I thought that happened because their parents encouraged one rather than the baby doing it
The only parent-led routine I can think of is Gina Ford and any suggestion of a GF routine on MN is usually massively flamed. It is fair to say these kinds of routines are not received positively on this website. GF herself I recall tried to sue Mumsnet for negative publicity on the forums.
However lots of babies do follow routines. Realistically these only work if you follow your baby's lead and just watch and encourage your childs natural rhythms.
Noticing the babys own rhythms requires some active paying attention. For example many Mums will notice, for example, my baby usually cant stay awake longer than X hours/minutes. You cant know that without actively paying attention to the baby and the clock over a period of time.
No baby will stick to an exact time rigidly, but it gives parents and idea so that they can begin to predict when baby will probably next be tired - give or take, and approximately. Not my the clock, but by time awake, for example.
On from that, parents can usually then start correlating time awake to time asleep - so predict next nap time on the basis on previous nap. Again, this involves active paying attention to the baby and the clock.
The routines you are reading are more about parents learning to be able to predict their own child's needs. They are baby led though, gained by watching how the baby behaves not from the insistence of a parent.
Having said that, once you are able to predict your baby's baby-led routine - you can then (if you need to) manipulate it to suit. For example if I knew my DD refused sleeping in the pushchair and can manage 80-120mins awake time before she's tired again and rarely naps for longer than an hour - I might work hard to get her to sleep for 2.15pm so that when we go on the school run at 3.15 (to pick up her siblings from school) that she isn't tired.
sometimes he has 3 meals sometimes he doesn't, it depends
That's just his age. Food needs just be for fun and discovery until 12 months old.
Even once on a full diet and needing 3 meals a day, "mealtimes" are usually fluid for babies and toddlers. Much of this fluidity is because sleep affects when meals can fit into the day.