The nobility of Europe often used French as their language of choice (the Russian royalty were still using it when they fell), and the
Tintin at Sea exhibition gives examples of figures contemporary to Sir Francis who would French-ify their names when writing in French.
It also posits that Hadoque was a Scottish Jacobite, who would have allegience to the Scottish monarchy, and therefore to France through the "
Auld Alliance".
In a recent review, someone said that they thought Haddock was given a Scottish accent in the old cartoons. I don't really know if Haddock is English in the original, or just British (
Anglaise covers both, in that grey way
English is used by many English people to mean
British).
Archibald, although Germanic in origin, is a common name in Scotland.
As I said, the word
anglais can just as easily mean "British" as "English". Given: that he drinks whisky; that the
Karaboudjan (or at least its real-life model the
Glengarry) was from Glasgow; that a credible case has been made for Sir Francis as a Jacobite; that "Archibald" is a fairly common name in Scotland; that there are historical links between the Scots and the French; that there is a long history of Scots stereotypes as ship's engineers; and more importantly that I happen to
be Scottish, I make a (fairly partisan) claim for Haddock being a Scot!