I know Giovanni, who comes from Geo, meaning earth. Here are my really bad theories for the rest:
Maxie kinda sounds like Maximum Potential, which is what he is trying to get Groudon to, it's maximum potential.
Archie sounds like Arch-enemy, and Archie is Maxie's arch enemy.
Cyrus sound like Cyprus. The doctor in doctor who has been to cyprus (in the old series). The doctor goes through time and space, and Cyrus wants the Pokemon of time and space.
N's full name is natural something something (no, its not actually that, but I can't remember the rest.). N loves nature, so thats could be where his name is from.
Ghetsis sounds like Get This. My theory is that the guy who officially gives people names was also a kidnapper with bad hearing. When he asked mommy Ghetsis what the baby's name was, she said GET THIS. He's my baby. You cant steal him. The name giver didn't hear the last part, and though she said Ghetsis, so thats his name.
My theory for Lysandre is that when he was young, his name was Dre and he didn't take care of his hair. with hair that big, he was bound to get lice, so people called him "lice on Dre". The name then stuck, and he forgot his name, and Lysandre was created.
These are jokes, and I know that its hard to tell sarcasm when you're reading something, which is why I'm telling you. What are these guy's name origins?