Building on the back of a successful lions tour and RWC. If the Shute shield was to expand and grow where does the next club come from? Blue mountains have been strong in subbies land, is there an Illawarra team? Canberra vikings again?
Any Subbies club would have genuine issues with depth and quality - the First Grade sides in Subbies might end up mid-table with a Premier Grade 2nd comp if they had a good year. It'd be like Joeys playing their 3rd XV against Sydney Boys high, and still winning handsomely on average.
Taking a team from another comp weakens that comp, and creates logistical headaches for everyone in the main comp.
Stabilising what is there already is the best way forward, as well as looking seriously at the structure of the competition.
4 Grades + 3 Colts is highly questionable IMHO, particularly as it means playing at 2 different venues.
All clubs need to get a competitive Womens XVs on the park as well. Right now that isn't happening and SRU are responsible for that.