
I do see what you are getting at, you are thinking of a possible configuration as follows:
VCC to Douglas - Evergreen Line
Waterfront to King George - Expo Line
Waterfront to Lougheed - Millennium Line
Now, the problem with this is that when the extension of the current M-line is made west to Broadway / UBC, that means Coquitlam will be given as frequent a service as Broadway, which I doubt it will need, as the routes would become:
UBC to Douglas - Evergreen Line
Waterfront to King George - Expo Line
Waterfront to UBC - Millennium Line
This would give both the Expo line portion from Waterfront to Columbia and the Millennium Line portion from UBC to Lougheed max available frequencies, as these will be our trunk lines.
While this could work, I still think that considering Surrey's potential future expansions, and the sheer population south of the Fraser, it would be best to keep the configurations as I proposed earlier:
VCC to Douglas - Evergreen Line
VCC to Columbia - Millennium Line
Waterfront to King Geogre - Expo Line
Which would become this in the future:
UBC to Douglas - Evergreen Line
UBC to Columbia - Millennium Line
Waterfront to King George and beyond - Expo Line