No. I can remember when 3-terminal regulators were the latest thing, but I've never run them in parallel. If you need that much current, either you use a higher current regulator, or add an external pass transistor.
What you're missing is that 3-terminal regulators were originally called "on-card regulators". The intent was that you'd have one raw voltage source, and distribute it to the various boards. ON each board, you'd regulate with one of those 3-terminal regulators. That provided a level of isolation between the boards, and meant you didn't need some massive regulator and heat sink to feed it all.
If you really need more current than one switching supply supplies, then don't be cheap, and buy a higher current switching supply. Or rework the circuit so you can use two power supplies to feed separate parts of the circuit.
Or rethink things, because you may not need a regulated supply, since a lot of real current hogs don't need regulation.
Don't pass off hobbyist stuff as a design issue.
Michael