My family name is Gedeon, and I think it makes more sense to write it in Latin characters as 'Gedeon' instead of 'Gideon', given the spelling commonly used. However, most French/English speaking people in my country still find it hard to spell it as it's meant to be spelt, and when they want to write it down without my help, they would write it as 'Jadaoun', which I really dislike. Arabic, being richer in spelling, restricts the spelling to one. If you can read Arabic, it's 'جدعون' Since 'Gedeon' in etymology symbolizes the 'father of war', I have named my little one Axl which means in Scandinavian the 'father of peace', creating a balancing oxymoron:)
Someone has said this name is pronounces ghee-dohn, but I have only ever heard it pronounced Gid-ee-uhn. I have attended a Christian church for many years and have met many Gideons, always pronounced in the latter way.
Source: https://en.wiktionary.org/wiki/Gideon#Dutch (in English) [noted -ed]