[English Bowman]

I'm sorry Barry, but I don't agree with you there. You could argue that an Olympic bow is closer to a longbow than a compound, for instance;
A longbow, and a recurve both increase in weight the further you draw, a compound lets off, this makes a dramatic difference to the feel of the shot.
A longbow and a recurve are both shot with fingers, compound archers tend to use release aids.
A compound can use a peep and scope, these are not allowed in any other discipline.
A compound can use an overdraw, this is not allowed with a recurve or longbow
A compound can use a spirit level; this is not allowed with a recurve or longbow

I personally see archery styles as a line with Longbow at one end and compound unlimited at the other, American Flatbow, Mongolian style recurves, modern recurves with and without sights and compound barebow and limited are all points along that line. Take a look at this quote.

"Standing, knocking, drawing, holding, loosing, whereby cometh fair shooting, which neither belong to wind nor weather, nor yet to the mark; for in a rain and at no mark, a man may shoot a fair shoot." Toxophilus : Roger Ascham : 1548

I think that the above comment can be applied to shooting any bow; it's all just variations on a theme.

Cross discipline coaching working depends on the level that you are coaching at.

You can teach any style at the beginner/intermediate level, there are some differences in techniques needed to shoot well in different bows but these are small and easy to understand.
I coach all disciplines, and have had archers win county golds with longbow, recurve barebow, and Olympic recurve, and silver with a compound.
I will not coach to a higher level than county standard as I feel that after that I am holding the archer back. Once an archer makes it to the county squad, I pass them onto another coach.

I feel that once someone has reached county level they need a specialist coach who understands the specific problems and techniques of that particular style to take them any further.

Having said all that, I do accept that there are some coaches who do not understand these small differences in style. These coaches either teach everybody the style that they (the coach) are comfortable with, (usually Olympic) no matter what bow is being used, or refuse to teach any other discipline
I don't have problems with coaches refusing to teach the unfamiliar styles, as long as they point the archer in the direction of another coach who can help them, but I think that those coaches who think that the bow makes no difference at all to the technique used are in need of a refresher course.

Daniel