6 months old and still 4 naps?

[Ryan&HollysMom]

hey, got a question for you folks:
ryan used to nap at 9, 12, 3 and a catnap around 6, with wakeup in the morning around 7/7:30, and bedtime routine at 7:30pm, asleep usually between 8/8:15. this was our 3 hour EASY. now that he's eating solids twice a day (like a piggy) and started to struggle with the catnap, we had adjusted his naps to 9, 12:30 and 4, (and bedtime was a bit sooner) but all of a sudden he started sleeping shorter (particularly in afternoon) and was quite cranky in late afternoon and especially after 5, he sometimes woke up crying from that last nap. also started to wake up around 6:30 am. i know these are classic signs of being overtired. i'm thinking of putting him down 4 times a day again, cause before that he was NEVER cranky. i'm just wondering, is it normal for 6 month olds to still need this many naps? i'm reading other posts, and most parents are trying to go from 3 to 2 naps?!
the naps are anywhere between 45 min. and 90, mostly longer in the morning and shorter in afternoon.

[Ryan&HollysMom]

forgot something:
was thinking maybe see what his mood is like, and how he slept at night, and what is planned for the day to determine 3 or 4 naps. is this a wise idea? will it make matters worse?

[Ryan&HollysMom]

here's the routine:
7/7:30 BF
8/8:15 Cereal
9 Nap (45-90 min)
11 BF
12:30 Nap (usually 45 min)
2 BF
4 Nap
5 BF
6/6:30 Veggies, Fruit for dinner
7:15 bath
7:30/7:45 BF and bed

for awake time we go for long walks, play with toys at home, read books, go to storyhour at the library or playgroup at early years centre, run errands and he watches me cook etc.
this routine works great but he's soo tired by the end of the day, sometimes wakes up crying from the last nap, and then is pretty whiny at the end of the day. bath time usually makes him all chipper again cause he loves it, but dinnertime is a trial as of late, as feeding can't go fast enough, doesn't want to be in chair... maybe this is normal, i mean i know most children have a cranky time, maybe i'm just not used to it cause he was never whiny before.
he was 9 days early, planned c-section, has always liked to sleep.

[Ryan&HollysMom]

but doesn't this only work if he actually sleeps 1 1/2 hours? the way we have it set up right now he gets between 2 hours and 2.75 hours of awake time between naps (this if he only sleeps 45 min at naptime). theoretically it should be perfect.
also, i have BF times in between there (2pm), which i can't move yet until he eats solids for lunch as well.