My 5m DS has had disturbed sleep since about 2m, just now (last few days only) his schedule is sort of..
7:30 wake up for the day
9:00-11:00 nap
14:00-16:00 nap
19:00 bed
Wake ups at 20:00, 21:00, 22:00, 00:00, 02:00, 04:00, 05:00, 06:00.
He's always slept lots during the day, and I've never seen much difference in his night sleeping when he has lots of day naps or just a few. His behaviour is just much worse with less sleep. We've had days with as little as 45mins total sleep, and days with 6 hours of napping.
He only sleeps as long as he does during the day because I'm holding him. If I put him down to sleep we'll usually get about 20-45 mins each nap, and more maps through the day (used to be feed/sleep every 90mins).
Bad nights he wakes every 45-90 mins through the night, past few months a good night has one 3 hour stretch of sleep. Best nights ever were around 2 months old when he'd go about 5 hours.