At this point I'll settle for a transportation despot.
A hybrid system is about as far as you can go starting from here. Let every city keep their transit systems (if they want to), but place operational decisions like routing, frequency and fares policy (along with fare collection) in the hands of Metrolinx. The local agencies then contract with Metrolinx to provide buses/LRT/subways on a cost-recovery basis (or cost less municipal subsidies). With the money flowing into and out of a single party you end up with a tfl-type scenario where the central agency contracts bus routes to private operators, but in this case the operators would be municipal (or potentially a public/private mix). Freed from petty city-level politics Metrolinx would then have the power to implement fully integrated transit.
But fuck it if "a subway in every icebox" isn't an easier sell.