While I was working on a build system for our company I also tried to use "Ivy project" type jobs. However, I found out that Ivy project jobs have limitations against the Free-style jobs, for example it imposes using the Ant Builder but I needed to run a shell script.
So, we use Free-style jobs and set the "Trigger the build of other projects based on the Ivy dependency management system" Post-build action. I would recommend you the same.
