Bant Control is loaded with free countermagic (Force of Will, Force of Negation), making Veil of Summer's hexproof-from-blue and uncounterable clause extremely valuable, so keep all four copies. Boseiju gives us a way to destroy a Karakas or problematic nonbasic land, or blow up a Leyline Binding holding down one of our permanents, at low cost. Thoughtseize proactively takes a Force of Will or removal spell before our key turn, since they have very little way to punish sorcery-speed discard. Song of Creation and Runehorn Hellkite are cut since this matchup is decided by resolving a fast, protected combo turn rather than grinding, so we favor cheap disruption and utility lands.