Right now London's city limits don't make a lot of sense in my mind. In the north, you have development right on the city limit edge. In the south, you have farms upon farms.
London and/or the province need to decide if it's a urban centre or a metro amalgamation.
There are also lots of nearby towns growing and commute to the city but don't pay taxes.
If London was a regional municipality, then these communities would be taxed/influenced.
Here's my idea of a rough expansion of the city limits. This could be the regional municipality or just a single-tier city.
If it was a region, this bubble could expanded to absorb more areas in London's CMA and beyond like Strathroy, St. Thomas and Ingersoll.