A few immediate thoughts.

1.  Sounds like a lot of extra work.

2.  There was an earlier problem with fields created in Field Manager and then bound to by LEs.  I don't recall the particular symptoms, but it was supposed to have been corrected in one of the following releases.  I can't confirm that it was fixed because after having the problem, I stopped creating fiels in Field Manager because I no longer trusted it
Edited comment:  Erika has confirmed below that this old problem was fixed and this should not be a concern.

3.  Creating the LEs creates the fields.  So why not add the LE's in the same order as you would the Fields.  Then you can rearrange the LEs on the forms.  Arrange them in groups so you can use that form for data dictionary support.  Now make multiple new forms that you want, picking form the "Biound To" names that will now be there from the steps above.  Skip those fields that you don't want on any particular form, but you still have a form containing all the Fields for importing/exporting regardless of what other forms they might be on.

Thanks, Bob, that sounds sensible.  Forwards and backwards, I'll eventually get my mind wrapped around this.
Diane