I think you are definitely doing the best that you can do here. Great job!
Truthfully, that is a LOT of sleep for an almost 2 year old. Unless he isn't sleeping at all at night (and I mean, AT ALL) that would be something of a concern for me. Is there anything else about this little guy that doesn't seem "right"? Physically or behaviourally? I could just be reading too much into a bad parenting scenario...