slice size = 54,969 tokens (LateWar length); Napoleon = 22,083

baseline LateWar <-> Napoleon: 36 shared (per 10k Napoleon types: 17.5)
BoM slice 1: vs Napoleon 22 (10.7/10k), vs LateWar 52 (10.3/10k)
BoM slice 2: vs Napoleon 35 (17.0/10k), vs LateWar 72 (14.3/10k)
BoM slice 3: vs Napoleon 19 (9.2/10k), vs LateWar 114 (22.6/10k)
BoM slice 4: vs Napoleon 33 (16.0/10k), vs LateWar 71 (14.1/10k)

BoM 55k-slice vs Napoleon: mean 13.2/10k (LateWar vs Napoleon, same footing: 17.5/10k)
BoM 55k-slice vs LateWar: mean 15.3/10k