if your mother language is mandarin, you`d better use Xia for 厦.
if your mother language is cantonese, you`d better use Har for 厦.
Any PINYIN is for pronunciation purpose.
and any language should be protected.
so, for most the time, cantonese should follow those method in the author`s article.
while, if you are mandarin, you should follow chinese pinyun method.