Inconsistent attack combo damage

[Puttanesca]

Sometimes it seems less damage is done that should be for some combos.
For example Mama and Son + Ultra Fishbunjin 3000 should be 1+2+1 for a total of 4 damage right? Seems to do 3 damage.
Seen similar combos do 1 less than expected sometimes.
Has anyone else seen this?

[Puttanesca]

Oh never mind, always forget its the number of attack cards not the number of attack symbols that does the damage.