I think he's doing fine, Ted. As he has just started, he may change his allegiance in the next couple of years, so I would keep it fairly broad until he hits secondary. (At one point dd1 was ready to give up ballet as she wasn't enjoying it as much as she had, then she started pointe) ballet is crucial for the technical aspects of pretty much everything though, so it's enough to make sure he is getting a good grounding.
Dd1 dances four nights a week (few different ballet classes, tap, modern - she ditched jazz and lyrical last year) and is a stand in teacher for the tap class (she TAs the two junior classes) plus the odd weekend day in comp, exam or recital season.
Discuss with his teacher how he can be expected to move up through the ballet syllabus from this point - but there is really no need to panic. How many boys are at your dance school? Are they used to dealing with committed boys? (Ds1 dropped ballet as the girls in his class were too young to understand the need for male dancers and told him he wasn't welcome - it's great that your ds is so committed!) the teacher should have some sensible things to suggest.
Three different ballet schools for a six year old is unnecessary. It's fine if you have the money and the temperament to believe that all that is necessary, but it really isn't. Talent will rise to the surface and they can start auditioning once they hit double figures. A couple of girls from our dance school have been picked up for summer school by dance companies through auditions, and have certainly not been dancing at that level of intensity since reception.
And the interesting thing is that obviously more boys come to dance late, and statistically they stand more chance of becoming professionals with less intensive training. Obviously, in secondary school he will need to start putting some more training time in, but there is really no need to fret at 9, in the first year he has shown an interest.
The more kids you have, the more complicated the juggling is, and expensive... My other two don't dance as much, but are as horribly overcommitted as Alina's kids. Swimming, skiing, karate, ballet, hip hop, tennis, golf...
I do wonder in ten years how much money I will have spent on completely unnecessary activities 
Dd1 will use dance teaching as a pt job to put herself through university. She wants to do genetic engineering.
Relaaaaaaaax! And hooray! Another boy finds dance!