After locally patching Issue 2219, i stumbled acrosss the following:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=834225

This prevents ifup from exiting successfully which again makes netcardconfig
unhappy.

Fixing the symlink manually by itself does not help, though:
aoe-discover expects the aoe kernel module to be loaded.

The package does that using /usr/lib/modules-load.d/aoetools.conf which has no
effect
on a grml system as grml does not (yet?) use systemd-modules-load.