Right now a huge proportion of the Central Belt's rail network is dependent upon the two tracks and the flat junction of Hyndland to Partick, and it's only going to get worse as the Cumbernauld, Whifflet and Shotts lines are electrified and almost certainly diverted to the low level stations (even if they don't go so far as HYN-PTK, they're still going to be affected by troubles there).
Completely grade-separating Hyndland East junction and 4-tracking between there and Finneston is the only way to fix this - and once you do, you remove a bottleneck without any sufficient diversionary routes. Obviously there are other 2-track railways with higher complexities and frequencies (i.e. Thameslink) but unlike London, where there are diversionary routes via the Tube etc, there is simply nowhere else for the trains to go from the West as Westeron/Anniesland to Queen Street isn't electrified and there aren't enough paths to have services terminate there instead anyway.
If I were to do it, I would firstly move Jordanhill westwards to Westbrae drive as has been proposed. This would allow the Up line to go up and over a lowered Anniesland Down line, and would allow the Maryhill line services to serve there once electrified and reconnected southbounds through Anniesland, via the current ECS-only chord. The alignment through Hyndland is wide enough for four tracks already but there would need to be some demolition of the retail park on Crow Road and across Dumbarton Road too to allow a second bridge span to be built. At least some of the housing development to the southwest of Partick would have to go as well but presumably the new station build could include new residential work as well due to the enhanced service it would provide. Then it's just a matter of widening the viaduct since Finnieston is already grade-separated.
If I were to do anything else it would be to build a tunnel connecting the former Whiteinch Victoria Park spur to the Glasgow and Renfew District Railway spur at Braehead to allow a station at the new Southern General super-hospital and a permanent public transport link between the Clyde on the western side of the city.