Two entirely different and mostly incomparable groups.
Firstly, the SNP is a part of government in Scotland with representation in just about every electable body they could hope for. Strip away the independence movement, and the SNP are just a progressive centrist party, maybe a little bit to the left. Very electable in Scotland given the demise of Labour and quite a good record in office. The Eurosceptic movement doesn't have that. Sure there are some Tory MP's (and one or two Labour?), but aside from that what are you left with?
UKIP - party is a mess, can't even agree on how to campaign for Brexit, never mind get their house in order to become a real force.
English Democrats - more left-wing version of UKIP
Secondly, Scottish nationalists are going to win their battle in the end. Not sure if that is the case with the Eurosceptics if we vote to remain.