level, from, and count in xsl:number

Is there anything the level, from, and count attributes of xsl:number do
that can't be done more easily with the expr attribute and position()? 
I am looking at these three right now, and they seem to be superflous,
perhaps having been help over from the previous draft without a lot of
thought.  They're only used when expr isn't present. Is there any reason
not to make expr mandatory and remove level, from, and count from the
spec?

 
+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@xxxxxxxxxxxxxxx | Writer/Programmer |
+-----------------------+------------------------+-------------------+ 
|               Java I/O (O'Reilly & Associates, 1999)               |
|            http://metalab.unc.edu/javafaq/books/javaio/            |
|   http://www.amazon.com/exec/obidos/ISBN=1565924851/cafeaulaitA/   |
+----------------------------------+---------------------------------+
|  Read Cafe au Lait for Java News:  http://metalab.unc.edu/javafaq/ | 
|  Read Cafe con Leche for XML News: http://metalab.unc.edu/xml/     |
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