Rules-wise, it is perfectly acceptable.
Fluff-wise, it might need an explanation of why a small number of each Cult were together but is possible.
Using different troops for different things is a valid strategy (the Eldar are heavily based around it). How effective it is with CSM will depend partially on your plan for using them.
Fluff-wise, it might need an explanation of why a small number of each Cult were together but is possible.
Using different troops for different things is a valid strategy (the Eldar are heavily based around it). How effective it is with CSM will depend partially on your plan for using them.