Barring those who fancy they are putting on the style, native English-speakers prefer the shortest route.
Examples of preferring the shorter way:
Do you say 'WENNS-dy', 'WED-nez-day' or even 'WED-'nz-day' as a few do?
Do you way 'SEV-ral' or 'SEV-er-'l' as a few do?
Syllables with vowel-sounds like
'eh-ee' ie 'a',
'ee', ie, 'e',
'ah-ee' ie, 'i',
'oh-oo' ie, 'o', and
'yew' ie, 'u' are harder to say than
'ah',
'eh'
'ih',
short 'aw' as in 'cot', or
long 'uhh' or barely any 'uh' like the schwah-sound in the 1st 'a' in 'parade'.
In different, unstressed English syllables, the schwah can replace a lot more than one vowel. That means depending on the unstressed vowel, the schwah can replace a 'a', an 'e', an 'i', an 'o', or a 'u'--just not more than one per unstressed syllable.
In the US, some speakers accent 1st syllables in words like 'idea', 'hotel' and many others, with quite rustic effect. That is how 'CUE-nard' strikes me. As to words not stressed on the 1st syllable, I doubt un-posh Britons wanting to sound posh, ever imagined how hickish 'jag-GYEW-ahr' ie, 'jaguar' sounds. The disease spread to 'gyew-WAHT-erh-ma-la' [Guatemala] 'bye-LING-gyew-'l [bilingual] and other gems. Same applies to to 'KYEW-nard'. It's just harder to say.
Yet, one contributor who would surely know says Cunard ship captains say it as 'cue-NARD'. The 'yew'-pronunciation is the hardest for a 'u' and doubly so in a stressed syllable. Cunard ship captains apparently go easy on themselves putting the 'yew' sound in 'Cunard's' 1st syllable and leaving stress for its last syllable.