you have helped people, including me to get netctl running by stopping conflicting software that is using the network. I am concerned that although the instructions make it clear that there is conflict with netcfg, that doesn't seem to be the only source of conflict and a lot of time must be being wasted trying to track down the problem. The log files are not specific.
In my case netctl would not start ethernet-static because there were two dhcpcd systems running. I don't know to whom or how to suggest that the netctl instructions be extended to find conflicts and disable them. Perhaps you do.
Thanks for the help I got from you.