No worries, it can be done either way. Buying a compression tester is not expensive, and I think it is a reasonable suggestion -- don't you?

If one has plenty of time, the "try this" method is plenty fine. I've been using that method for my carburetor problem lately. On the other hand if you don't have spare parts it can get expensive buying new cap, rotor, plugs, etc only to find they didn't fix the problem.

For spark plug wires, a visual inspection will often find the problem, and a simple voltmeter will usually find the rest. Look for signs of burning (white or black marks) along every mm of the wire. Also look for a corroded cap terminal or plug wire terminal which indicates a firing problem with that cylinder.