In Sweden when I started students they were 9 years old and back then we did not start in a band. We started in small groups. A group could be 2-3 students on trumpet or trombone. A lesson could be 30-40 minutes depending on size of the group. After half a year I started a band and then woodwind and drums completed. Here a teacher usually is either brass, woodwind or drums in US as I understand you have ONE who teach all? The model here later changed and we started a band with all instruments right away, parallel with group. The band was then a collaboration of two ore more teachers covering all the instruments. Our books introduce notes in an order that makes it easy to play the easiest songs. The books has rythmic songs with just one note and then two note songs. The "real" songs need at least three notes. With five notes you have a good repertoire. At that stage we often introduce the alternate F on pos 6 because this is a help a student need in the beginning. In Sweden we let students borrow (hire) instruments as they start. This is to make it possible also for families on a budget. We did not supply instruments with f-att in the beginning at the time I stopped in 1999. Usually a student buy his own instrument after a year with the advice from his teacher. At that time an f-att trombone in brass will still be heavy to hold for a 10 year old so often a straight horn was the advice. When students continue to play they often reach Bb over the staff within a year so then they have a register between first pos (b)
and first pos (b) 
and they play songs in the key of F and Eb. 5th position is introduced at first with f# but this note isn't very common in the beginning. It is because a #f often implies the key of G if not g-minor and then the material of notes needs B on 4th. This important note needs to be introduded early but many students haven't got that streangth when they are ten. To introduce Bb at 5th position is absolutely something you could do at the same time as Bb on first but if you do then all books we use still tell the student that fifth pos is an alternate position for Bb on first. It's not that easy to change what's printed in hundered of books. If you teach adults it is different from teaching kids and this is from experience. Anyone who starts to teach have to face pedagogical issues that depends on context, and you can not just present facts you need something to motivate your facts too and you need to make it fun. Adults is different. Here I still need to accept musicians use the name H for B-natural, and if a flat is used they then call that note B. The B english speaking people call B-flat (Bb). Such things do also exist in books and need to be addressed. It might need a lot of reasoning to explain a mistake like that and why it is considered a mistake. When I stopped to teach many educaters still teach the old names. I hope we in the future can fully adopt to what's more sense and not to be that conservative about what's history. Sure there will be a lot of litterature that will be confusing but this will be confusing anyway. It was an old error that needed to be corrected. My way of looking at it.Since we did not start nine year old students on f-att trombones we had no need to consider teaching C on T1, B on T2 and Bb on T3. Today when things are different scools might see it differently. There are now cheap plastic horns that are easy to hold for nine year olds so it might be better for a lot of reasons to start on a cheap easy to hold f-att horn. To use these in our education also the books need to change because you get a lot more notes within reach. You could introduce C on T1 and B on T2 and suddenly you can play a lot more tunes within the staff. This could help motivation a lot, because students need to play melodies and get a repertoire. When I think of this a g-att plastic horn would do even better. Suddenly you can get ALL notes within the staff without passing the bell with the slide. With short arms you could play any tune. I know some has tried to start students on alto but a g-att horn would be a lot better, what I think.
In the end you should learn the notes on any position even learn the factitious notes) because it helps, but I do not see a problem to refer to some positions as regular positions and some as alternate. When you are ready to learn alternate positions you need to work at them so you can use them everywhere it helps. If you are introduced to all the alternate positions at once, when you learn a new note it is better, but the books to do it didn't exist in 1999, maybe they do now. If you're school supplies f-att plastic trombones you need new education material to make a better use of the trigger. You need completely new material because the books are made for straight trombones. That would be a good thing to do, to mordenize the books to make better use of the tools that's now available. Unfortunately there are not much money to get from doing this, and the plastic f-att trombones need to be a part of the whole concept right from the start. Could be interesting if it happens. I think the idea must be established from the collage educational system for music teachers/trombone teachers before it becomes comnon practice. Before this happens I think you better write your own book and start this journey on your own. Not much money in this but you might do some important grass root revolution to the education system that eventually will hit the collage teachers and be picked up there, but don't count on it to be easy. Unfortunately there are not many who choose to start on a brass instrument in the public music school and from those who start there are even fewer who choose the trombone. When I were a teacher I had one student on trombone for every tenth I got on trumpet. In tuba and french horn there were even fewer. To revolution teaching and write your new material based on all students start on a f-att plastic horn will be a slow process and before any evidence of a better result is there it will take years. How can a better result even be measured? Less who quit? Student can play more songs in less time? More audience on student concerts? More in the audience who appreciate the result?
Yes, a C on T1 can be a real opener, because it demands f-att and if you think of it a f-att can do a lot of good to all early trombone teaching IF the f-att makes the instrument easier to play and still is easy to hold. That's what I get when I'm reasoning like this, and even better with g-att. Go for it!
/Tom
