I've used a similar rush deck, sometimes with a few earthquakes, sometimes just creatures. 6 shriekers are way too expensive in my opinion. The comment about the golems is strange, because 2 golems give 8 attack for 8 quants, while 1 shrieker is the same cost, but with very low HP.
The difference between all these decks is negligible. 18 pillars and 6 graboids/ 6 shriekers is fine too, because then you can easily afford the shriekers. When people start cutting in the pillars, they all want to add golems or antlions.
Golems can't get through gravity shield...but they can take a hit and they can't just be eaten. I've done 6 graboids/3 shriekers/3 golems/3 earthquakes, or even 6 golems and no earthquakes and it all still works.