As long as you are sourcing your stock locally, yes, they will be "fine". They will have been kept in tap water locally. The species you mention are very adaptable. I had tanks with these fish in them with chalk borehole water so hard you didn't pour it, you sliced it.
They will never be in optimum condition, hence the quotes, but very few aquarists are in a position to offer optimum conditions to many of their fish. You do the best possible, keep it clean and your pollution levels low.