both are fine/still works, slight buffs since old builds
i think technically Rimetongue was technically slightly better as pierce now? (busted?) but cold nado saboteur was similar strong enough too for Lee to post it [1.2.1.2] The Saboteur: a Cold War Story, 4:05 Crucible Gladiator 150-170, SR 90, Celestials and fast SR 75-76 - swift and deadly Cold caster Saboteur
I don’t recall any recent Harra builds/posts because not much changed on that front, so same ol’ with whatever consideration tweaks for slightly more defensive meta i suppose
Aside from that it might just be simple class differences, like “not” doing harra sorc to do both CT and SJ. Not because you can’t, but because funnel approach into 1, eg cold CT breaker/cold SJ sabo might simply/“technically” be slightly more optimal, with the usual considerations for buffs/RR/passives.
Likewise why Rimetongue Sabo might be slightly better/“more optimal” choice than Purifier, so that’s why Lee did that, not that a cold Purifier version couldn’t be done.