Success at last!!
Hey guys, it's me again. And this time, I come with good news! I have successfully implemented the 'Club Transfers' tile and now, it's working as it should. I had a great deal of help from the awesome Fidel himself! Without him, I would still be stranded.
Here is a video of the mod in action
https:// jmp .sh /v/1JYIhh4dYVd6RTrEnUVj (Sorry about all the spaces. Or else the post won't show up)
For the curious, what I did was just include a few lines from "mainfeflow.nav" (which controls the main hub of FIFA 16) to "mainmenuhubflow.nav" (which controls the career mode hub) after editing the "careermanagerhubcfg.xml" as stated in the OP.
If you are facing a similar issue as I did or you just want to test the mod, you could download the files from the link below.
www63 .zippyshare .com /v/riq9cGk5/file.html