The Necromantic "attack bonus" enhancement doesn't work on shambling corpse.

[RiseAgain]

I used that particulair upgrade to enhance my shambling corpse's "attack" and his stats remained unchanged. Incase it matters, it's the shambling corpse form with the helmet.

It did count incase you're wondering, the enhancement didn't "fail". It also counted towards the amount of enhancements I could apply to it, as I could apply additional ones to the one I didn't upgrade with attack.

It doesn't work, apparently. The attack bonus does work on skeletons.

[Pentaxius]

Indeed. The reason is the shambling corpse has already scripted bonus AB. Hence, any source of scripted AB lower than it's fixed scripted bonus AB will be absorbed by the former.

[RiseAgain]

Okay, I can live with it, so long as the DM's know of this.