In regard to the incorrect content ID claim for the song Jato (The Lion) by David Gilden. When you dispute a copyright claim, YouTube has you pick from a list of categories as to why you're disputing a claim and unfortunately incorrect content ID is not an option. I picked the "Copyright exception such as fair use", type of reuse as game play and in the comment, explain that the song being claimed is Jato (The Lion) by David Gilden and not Everything by John Hanlon as the content ID is claiming. I'm actually surprise that it got responded to as fast as it did and didn't just lapse with the 30 day they have to respond.
I don't know how receptive these companies are to usage of their licensed music in game play so I don't know if trying to dispute all the claims would be viable or worth most people's time. It's just easier to avoid for most, I believe.