Has anyone tried to "bundle" their OT rule sets so that many sets can be run at once?

We have many different Unions and they all have different OT rules.  These rule sets need to be run daily due to the daily cost reporting.  There are 13 different rule sets so it's quite time consuming.  I tried bundling all of the rules into a single rule set using the Call Rule Set rule.  It allows me to add each of the already defined rule sets to a main rule set but when I try to submit it, I get an error telling me I have an invalid record and highlights the Employee Group field.  Each of the separate