Slaves have had 10 new kits this year (underworld warband, 6 warcry warbands, chaotic beasts, new start collecting, endless spells).
Gloomspite had 15 new kits (2x underworlds warband, herd, hoppers, manglers, fanatics, gobbapalooza, snufflers, rockguts, trogboss, skragrott, loonboss, squigboss, terrain, endless spells)
Bonereapers had 13 new kits (crawler, riders, guard, harvester, arch kavalos, katakros, boneshaper, soulmason, soulreaper, vokmortian, stalkers, terrain, endless spells)
So slaves didnt have the most new model kits.