Well, Scolipede's set looks pretty good to me. When you say trio, I'm assuming you mean Triple battle?
Anyway, give Scolipede either Choice Band or Muscle Band.
Since it's a Wall, give it Leftovers.
U Turn is good
Try Attract, as Mandibuzz is always female
Okay, replace Darmintian with Carracosta, if you can. If you used your fossil on Archeops, well, I don't know. Maybe Jellicent.
Carracosta: Tank. Try to get Relaxed or Impish Nature.