I don't think GSM ever gets to block. Any creature vialed in will be bounced before blockers. Evoked Endurance dies immediately to itself.

But cat tokens being legendary is a good point. I think this means that the race is a bit tighter, and GSM will definitely get some attacks in while Karakas is clearing out blockers. I still think the cats do 3 dmg and gain 2 while Endurance or Bombardiers only do 2 or 3. This does mean that the ocelot is exposed to a thrown vial, but then the other cats have a clear path.