Upgrading abilities n Stacking Sicaros

[Naptownmark]

Benefits from several sicaros stack.
Benefits from several sicaros do not stack.

I'm confused by this is there a certain way it should be done.

When it says stack are u supposed to only combine 2 random sicaros with enough stars to acquire the ability.

When it says benefits from several sicaros do not stack.
I'm completely lost as to what tht means I just throw together the sics I dnt use n go from there.

 

[ELpatron50]

combining 2 identical sicarios=2x stars
however the abilities acquired are also randomized?
like using dice to randomly change the attack,defense,debuff skill slots.

 

[Naptownmark]

I figured it out, it had nothing to do with combining sics to get a talent. When they say dnt stack or stack they mean it's ok to use let's say a David n Parca at same time n battle. Others will say dnt stack n use 2 certain sics n battle. So I found out stacking had nothing to do with combining sics to get talents.