Issue with fewer giant bridges is that:
1) they suck for pedestrians and cyclists. Right now there is a 1km gap between the East Link and the Beckett bridge. That's a long way on foot. It means that you have two distinct areas north and south of the river with little commerce between them. This sort of blank wall tends to make an area pretty barren and sterile, city areas thrive on interconnection.
2) No point having bridges with huge capacity if the streets feeding them don't also have huge capacity, which the quays and the streets approaching the quays do not have.
+ 100, having worked on both sides in the area in question I can say it'll be a great addition and will make a big difference to non-car traffic.