Intro to the cards
To be completely honest, the only real attacking monster (Unless you can set up) is Triamid Sphinx. The rest of the Triamid, Gorgonic, and other monsters are support.
How to play them
You will definitely need one Field Spell in your starting hand if you want to do a big move. The playstyle for the cards can differ from person to person. Just a suggestion, try to get a Sentry Soldier of Stone into the Graveyard. It will help you XYZ summon a lot easier. Gorgonic Guardian is the main XYZ monster you'll probably use due to it's effect.
Weaknesses
Anti-summoning cards. i.e. Solemn Warning, Solemn Strike. These cards can completely screw up the summoning of the Sphinx.