Originally Posted by Drip

Actually, with 4 girls giving the 1.2 trigger rate increase and Cymbidium as the fifth girl, you get a trigger multiplier of 3.6 (1.8 for the normal trigger girls added up, times 2 for Cymbidiums' passive, since that one is multiplative, not additive with the normal passive). Next, you simply divide 100% by that 3.6 multiplier to get the minimum base trigger rate the girls need from their skill to get a guaranteed trigger, which is 27.78%. So yes, on turn 1, all of Matrix's girls are guaranteed to trigger.

Which also explains why Cymbidium in my trigger squad has a ~4% chance to miss: I have only 3 regular trigger girls 1.6 * 2 = 3.2 -> 100%/3.2 = 31.25%, and Cymbidiums' skill only goes to a natural trigger rate of 30%. All other girls in my trigger squad have guaranteed triggers (32-34%, so they're above the 31.25% tresshold). Or, 30% * 3.2 = 96%.
Obviously, I'm waiting for Fritillaria's bloom, which gives her a 1.2 trigger multiplier as well.

Where are you getting that Cymbi's ability acts as a separate multiplier? I didn't see this on her unit data here, nor on the DM wikia.