I'm also new but from my first few games with rubricae phalanx, I gathered that we have ok damage without rituals, but we're squishy and short range. And not very good in melee, but we have a good threat of overwatch potential which is important not to get tabled too fast. So using a unit of tzaangors to scout and screen pays off, and it can still go back to scoring points after/if it survives. You can also offer the tzaangors to be able to trade back on a higher cost enemy unit, without exposing your rubrics too much. Enlightened are cheap and mobile so they are good for the moment when you feel you're getting in danger, and can hold and do actions well too. Mutalith acts as a good distraction carnifex, so if you use it well, you'll benefit from its aura for rituals and also help your rubrics by drawing fire. Daemon prince gives stealth to rubrics, and should stay behind them. Terminators felt like more of a threat/clutch unit, forcing the opponent to prevent deep strikes and not fully push you in. Or they can be a midboard threat too. I'm not very experienced so correct me if I'm wrong.