As with many names there can be more than one pronunciation, and quite often its a matter of era, and fashion. Owners of my given name, Irene, who were born in the 1920's would have pronounced it I-Ree-Nee (some others still do) - I personally loathe that pronunciation. Neither pronunciation is actually more correct than the other.
In the case of Ralph ... Raife would have been the correct pronunciation for someone of RVW's age/date of birth and social status ... I suspect he would have found the current more common pronunciation just that .... common!
Out of interest, a particular Gilbert and Sullivan opera uses the name, and uses it to rhyme with the word "waif" ... but at the end of the day there's no correct way of pronouncing ANY name ... it's down to how the owner wants it pronounced (or even spelled ... cf Clare, and Claire ... both equally correct). So in this instance, not pretentious, just the correct way of pronouncing it.