Understanding hero stats global

Hello, i’m not really used to write in english anymore but i’ll try my best to make me understood…
I don’t understand how hero stats are added…
My hero base stats are 5 Attack 3 Magic 12 Life and 7 Shield

I’m level 2 in warrior class : 1A, 2L
I’ve selected the first one for Rakshas in the tree of skills: 2A, 2L
I’ve a bonus goblin’s Lord : 2L
Finally, I’ve the Pic’s Axe to the Max : 1A,2A,4S,2A,2A then 3 properties.

So the total should be 15A,3M,18L and 11S or my actual hero stat is 13,3,11,16.
I imagine it’s not a bug so how does it work, I don’ t find a clear answer…

Thanks