There is a few things that could easily fix geelong services.
1. Add a new station between wyndham vale/werribee and little river. Extend all werribee trains here. (needs to be at least 5 platforms)
2. add two tracks between the new station as above and newport (or further in)
3. duplicate as much of geelong-waurn ponds as financially possible. So it can easily maintain at least 20 minute frequency all day with the occasional warrnambool train to get through.
4. electrify all the way to waurn ponds, This includes the RRL
5. Send all trains to geelong via werribee, and tarniet line trains terminate at the new station.
6. get geelong trains to be through routed to at least flinders st. ideally have them terminate slightly further such as south yarra, or even integrate them with sandringham line. Major problem with v/line trains is forced transfers in the city.
7. This would be alot easier once the new metro tunnel is in operation.
8. this could all still work without electrification,but would need alot more velocitys.