Here are a few relevant things Weavile handles better than Mamoswine: -Starmie -Celebi -Terrakion -Gengar Starmie is the most obvious one. Mamo won't like Scald or Hydro Pump and Starmie can take an EQ. Weavile Pursuit traps it and actually has enough special bulk to live through anything that isn't a boosted Hydro Pump. Celebi is bulky enough to take an Ice Shard and retaliate with STAB Giga Drain/Leaf Storm. Offensive variants outspeed Mamo so Icicle Crash won't help. Weavile outspeeds and uses Night Slash/Ice Punch. If you predict a switch you can just Pursuit trap it too. Terrakion outspeeds Mamo and has enough bulk to live past Ice Shard, while Weavile is faster and can use Low Kick against it. Gengar can potentially screw Mamo over with the Disable set while the LO one OHKO's 70% of the time with Focus Blast. Weavile outspeeds it and Pursuit traps. Weavile revenge kills ice weak targets almost as well as Mamo (its attack is only 5 points lower) with the exception of Dragonite because Extremespeed will KO after SR. Against Lati@s Weavile is unquestionably better because it has Pursuit in addition to Ice Shard, giving it more options. Yes, Weavile is frail as shit (which doesn't really matter when its job is trapping/revenge killing specific targets) and doesn't have Mamo's bulk or STAB EQ but other than Ice Shard they're nothing alike and play very differently.