Scarab's Card Text is worded
n=Number of Scarabs you control at the end of the turn.
The n Refers to the N as it's HP (2|N).
If you wanted it to be worded like scarab than it should say:
2+N/2|4
n=The number of Skeletons you control at the end of the turn.
You have an "N", but atm you don't say what it is.
For example, if N were Death Quanta, and you had 8 quanta and 3 skeletons, It would get +12 (+4 attack for each skeleton.)
updated
This, taken literally, doesn't work that well either.
If N is the number of skeletons, and you get N/2 Attack for each skeleton, and you have as a random example 4 skeletons,
You would get 4/2 (2) Attack for each skeleton (4), or +8.
Sorry for criticizing, but I'm just trying to help.
Nice card btw.