You might say, then why not introduce a "seimhiu" character whose glyphic representation is either h-following or dot-above? Primarily for Unicode structural reasons: Unicode needs to say a character is either combining or not.
I proposed one once, long ago. When I didn't know anything about Unicode and ISO/IEC 10646.
--
Michael Everson * * Everson Typography * * http://www.evertype.com
