The article says the teams don't have the money to do it alone, and doesn't sound like much public financing is available in LA....it's the potential revenue streams in that market that make it attractive if you're going to finance a stadium. It sounds like the race is on.
Then neither is going to move.
The Rams are gone. Unless someone in LA manages to block Kroenke's project, that stadium appears to be a guarantee; they've already broken ground on the rest of the complex. Mike Florio has already talked a bit about how Kroenke very likely would go full Al Davis if the league made an attempt to block him.
They won't let three teams move to the city. If one of the two other stadium plans is still considered cost-effective after the Hollywood Park project, maybe the Raiders or Chargers can partner up. But most likely they will end up a tenant, and the other will either take whatever they can get from Oakland/San Diego or move elsewhere (probably St. Louis, if the state of Missouri does what they are saying and builds their planned stadium no matter what).