with that few pillars it's actually quite probably to have no pillars.
6 Pillars in 34 cards gives you a chance of 5% to have a no pillar draw (with mulligan), or every 20th game.
I'd go with the rule of thumb to never use less than 1/3 of your deck as quanta sources. Even with just 10 Pillars in a 34 cards deck, your chance to draw no pillars (with mulligan) is around 0.4%, or every 250th game.