So not sure how this shakes out. I bought FMS13 and connections for Go. We have 5 FMPro users in the office. I was told that the connection limit is 5 for FMP13. I also took a look at this link.
"Sharing a solution using FileMaker Pro 13 or FileMaker Pro 13 Advanced as a host do not require concurrent connections for FileMaker Go 13 clients to connect."
the concurrent connections seem to only apply to FMS13. I will give this a test tomorrow.
Maybe the limit is 5 connections from any type of client with FMP. I will figure it out tomorrow for sure.