I found a pic of a SMAC Defence platform.WWW Link
If you looked at it, you will see it has to be bigger than 3 or 4 frigates combined. Maybe we can have the SMAC platform a repair station AND a defence platform. It also has Hangers, so perhaps the SMAC platform can be like the Novalith cannon or the Deliverence engine. It has 3 things, defence platform, dock, and 3 small hangers. For the lowest def platform, we could have a regular MAC cannon, instead of SMAC.