I definitely think you could get away with a lot of these, but here are alternatives with nn suggestions in parentheses:
[name]Alfred[/name] - [name]Alfie[/name]- [name]Arthur[/name] ([name]Artie[/name]), [name]Archer[/name] ([name]Archie[/name]), [name]Asher[/name], [name]Ashton[/name], [name]James[/name]/[name]Jameson[/name] ([name]Jamie[/name]), [name]Albert[/name] ([name]Albie[/name]), [name]Oliver[/name] ([name]Ollie[/name]), [name]Ellis[/name], [name]Tennyson[/name], [name]Philip[/name]
[name]Aleksey[/name]- [name]Alexios[/name], [name]Alessio[/name], [name]Alexander[/name] ([name]Axel[/name], [name]Xan[/name], [name]Xander[/name]), [name]Gregory[/name], [name]Leo[/name], [name]Stephan[/name], [name]Anton[/name], [name]Anthony[/name]
[name]Amaury[/name]- [name]Ari[/name], [name]Andre[/name], [name]Armand[/name], [name]Raphael[/name]
[name]Bertram[/name] - [name]Bertie[/name]- [name]Abram[/name] ([name]Bram[/name], [name]Abe[/name]), [name]Frederick[/name] ([name]Freddie[/name]), [name]Vincent[/name], [name]Louis[/name], [name]Wilson[/name], [name]Otto[/name]
[name]Casper[/name]- [name]Emile[/name], [name]Porter[/name], [name]Cole[/name], [name]Julius[/name]
[name]Dmitri[/name]- [name]Dante[/name], [name]Max[/name], [name]Timothy[/name], [name]Dominic[/name], [name]Julian[/name]
[name]Guillaume[/name]- [name]Gabriel[/name], [name]Anatole[/name], [name]Luc[/name], [name]Thomas[/name], [name]Auden[/name], [name]Beau[/name], [name]Charles[/name]
[name]Hugh[/name] - [name]Huey[/name]- [name]Hugo[/name], [name]Henry[/name], [name]Luca[/name], [name]August[/name], [name]Ray[/name]
[name]Magnus[/name] (family name)- [name]Mathias[/name], [name]August[/name], [name]Atticus[/name], [name]Callum[/name], [name]Nolan[/name]
[name]Martin[/name]- [name]Devin[/name], [name]Flynn[/name], [name]Finn[/name], [name]Lucas[/name], [name]Eric[/name], [name]Simon[/name]
[name]Nikolai[/name]- [name]Malachi[/name], [name]Makai[/name], [name]Nico[/name], Niccolo, [name]Nicolai[/name] (to me, this spelling looks a little less Russian), [name]Kai[/name]
[name]Ole[/name] (family name)- [name]Joel[/name], [name]Omar[/name], [name]Milo[/name]
[name]Thor[/name] (yet another family name)- [name]Declan[/name], [name]Apollo[/name], [name]Cruz[/name], [name]Neo[/name]