I'm not sure if what "Gloval" means or if it's someones actual last name matter much, because I don't know anyone with the surname "Global" either, and plenty of last names have no "meaning." Although mine, shockingly enough, is a color...
However, classicly in Macross it's been "Global" and if that's the way you want to go, that's how it is. I know I'm always disappointed when he talks in Macross because I remember the RT "Gloval" so vividly as a badass when it was on long ago, having the last name be different isn't that big of a deal.
Except for the pornstar part. Oh well.