Goats, my DD would go down to two naps if we didn't have the school run disrupting her.
She currently sleeps 9.30am-11.30am (I wake her) and 1.00pm-3.00pm (again I wake her). Then she has a 30-45 minute powernap around 5.30ish. Wakes 7am, bed 7.30pm
She'd sleep longer in the morning if I let her, more like 2 1/2 hours. She'd also be happy staying awake longer over lunchtime so that afternoon nap could be pushed to more like 2.30-4.30pm. That would mean she could drop the late afternoon sleep.
In an ideal world I would be baby-led and let her sleep like this, without waking her. This is what she does at the weekend and in school holidays. But on school days I have to consider collecting my other children from school.
Because she sleeps in the cot and I have to get her up for the school run at 3pm, I have to fit all the rest of her sleeps around this. So that means making sure she doesn't sleep too long in the morning so she goes down early enough in the afternoon to wake for the school run.
Needlessly long post there, that could be summarised as no, it's not too soon to drop to 2 naps a day 