With good timing, you can have ONE try to land NSD.
Either it gets countered, and MP is dead
Either it lands... and if it lands, there's 2 possibility:
1 : trader didnt do anything while you were casting ... he's NSD, and MP is not rooted/debuff => trader kites the pets => trader lives
2: trader saw you cast NSD, and, if not stupid, will cast AoE root at the same time => trader lives
Clearly, MP is not a counter to traders...