reckon you'll more likley see a hundred Labour form some temporay coalition with the Tories than a Labour/SNP coalition. while they have simliar general policies, a deal would surrender Scotland to the SNP forever, precisely because they are similar. why bother to vote Scottish Labour?
Labour and Green has much less in common at their core, to deliver the ideals of green politics requires taking a axe to most of industry, all of which in some way destroys some part of the environment.
Labour changeed in the 1990's to something more social democrat, and should probably have changed the name more to reflect that. now its in an existential crisis because the MPs dont reflect the old Labour membership, there's very few real socialists around. rather than continue to fund it...