They need to sort out Long Rest first to make it the meaningful mechanic it's supposed to be. There's no beating around the bush with this one. All the classes have been balanced around Long Rest. It needs to have effective restrictions / tradeoffs / risks on how often you can do it.
After that the amount of Short Rests need to balanced with the Long Rest frequency. There's no point in limiting Short Rest until Long Rest is also much more limited somehow.
