If you're going for an attacker, go for Mamoswine. It still has 5 weaknesses though, but it's immune to electric types.
If you're going for a special attacker, go for Vanilluxe. It has a higher base stat than Mamoswine as well, but has only one less weakness and isn't immune to anything.
Having icicle crash on Mamoswine is good though, since it's a physical attacker and icicle crash is a physical move, plus it does stab damage.
In my opinion, I'd go for Mamoswine since it has a better learnset in my eyes. Just be wary that it might die fast.