So I've been sitting here trying to figure out what the bloody heck I thought I was doing when I stuck that u in his name, and it all came back to me. Specifically, Murchaud has two names. Or more properly, he has a French spelling of a Gaelic name. The proper Scottish spelling is "Murchad" or "Murchadh", and it's pronounced "mur-ach-a, with a gutteral ch as in loch.
The French version would be pronounced in the obvious way, as in Il fait chaud.
Gee, that makes perfect sense, now that I figure out what my brain was doing in 1990 or so when I named him.
And as for why he has a Gaelic name with a French spelling... well, that would be telling.