My DD is 7.5mo and has similar naps to yours. She usually has short naps of 30-60min in the morning and afternoon, and a decent sleep of about 2hrs in the middle of the day. The afternoon nap is hit and miss, sometimes it doesn't happen.
She sleeps well at night, usually from 7:30/8pm to 7:30am with 1-3 night feeds.
What sleep school did you go to? Seems a bit rigid trying to force 2hr naps! We went to Tresillian and they looked at the total sleep over a 24hr period rather than the length of each individual sleep.
I figure that since she sleeps well at night she doesn't always need a lot of day sleep. Also depends so much on what's happening in the day.