Originally Posted by paraphin

does the 1.2x skill activiation skill stack?

i'll lvl up cyranthus for my helper team. will add her on sunday.

Yes, they stack additively within the squad.
1 girl = 1.2 multiplier
2 girls = 1.4 multiplier
3 girls = 1.6 multiplier
etc.

The skill stacks multiplative with other activation rate skills. For example, Cymbidiums' 2x rate on first turn.
So, if you have 3 girls for the total 1.6 multiplier and add Cymbidium, then your activation rate on the first turn has a 3.2 multiplier. If a girl has an activation rate of 30% by herself, then that totals 30% * 1.6 * 2 = 96% for the first turn. Which is pretty nice while clearing maps, since they usually clean out the pests on the first turn. Against raidbosses, it tends to perform slightly less efficient (but still way better than a squad of random girls thrown together), counter and debuff squads perform better against those.