Team Synergy

Team Synergy is when vivosaurs in the trio work really well together. There's a number of reasons how teams can work together, such as skills, strategies, stat boosts, etc. Most vivosaur teams that work really well have a combination of good team skills, abilities to compliment each other and usually don't rely on many gimmicks. A good example of a great team with synergy is Compso, Dacerus and Cryo. 
# They all have overall very positive stat boosters, Dacerus having great attack and defense boosts and some small negative in speed but that doesn't matter, Compso cripples AZ, and Cryo has good accuracy and defense boosts.
# Abilities count, especially in this team. Compso has FP Plus, and Dacerus has FP Absorb. FP Absorb may not seem much immediately, but if you're getting hit by an AZ vivosaur with a massive move that will do nothing and you absorb about 80-100 FP because of it... That's potential for deadly combos.
# Their actual attacks pay off well, including Compso. Dacerus and Cryo both have poison skills, and Cryo has excite. It's great for wearing down and having them position locked. Compso has low FP high critical attacks, despite them not ever saying Compso has a high critical rate. Dacerus and Cryo can poison the entire team, immediately too due to the FP Plus being able to allow Dacerus to poison off the bat. Finally, Rallying Cry helps prevent many problematic ailements.
# For very competitive people, they all can have a Miraculous Fossil applied to them. This is big because that's 100 more health and 20 more stat points overall.
Keep these in mind when creating any team.