It makes no difference. Based on what was seen Laxus is stronger than Mystogan. That's clearly proven when he simply laughed at everything Mystogan threw at him when he wasn't anywhere near serious. You can't say one is stronger than the other when he's shown nothing that proves that and Mystogan has shown nothing to prove he's stronger than Laxus.
Mystogan doesn't have that strong of magic, which is implied when Jellal stated he couldn't defeat Jura using his magic. He is from edolas afterall and there's a very limit supply of magic in that world.
Hell Mystogan doesn't even have actual magic. He uses the staves he carries for his magic.
