Converge was so out of place on the Mastoklok tour because the last place a godly hardcore/grindcore/metalcore/noisecore band wants to win over new fans is opening for an adult swim band and Mastodon. The genre's just clashed a lot. Also, Converge thrives on more intimate settings. Try looking up some live videos from one of their headlining tours. Shit hits the fan.
01/12 - Zero Boys?
01/16 - Origin w/ Trog
01/24 - Into It. Over It.
02/09 - Amon Amarth w/ Enslaved, Skeletonwitch