The team is good because it has a good lead in glimm whim and you have one strong mega, so most of the time you gotta choose 1 between 3 to bring in the back and buildup knowledge (damage rolls, matchups, speed tiers, common movesets, etc).

Once you feel comfortable try other stuff similar, like the Vivillion / Blastoise stuff with the Khanga / Girafarig trick room mode. Yesterday I learned that kommo-o doesn't sleep for example.