Both versions have the same result essentially (24 points of damage) but one took a lot longer to get to while taking up the same amount of "game world" time.
No, they don't have the same result.
Firstly, none of those examples were from leader classes which makes the entirety of the argument suspect, but let's ignore that for the moment.
In your own example, the ranger added 24 points of damage to the equation and most likely prevented the 24 points of damage done to the invoker. If you recall, the Disruptive Strike power adds a penalty to the triggering targets attack roll for the triggering attack, and given the substantiveness of the bonus, it's highly likely to prevent the attack from doing damage. That and you said it only just hit the Invoker
Then there's the fact that without the 'cleric' in your example, the invoker wouldn't have a bonus to his defence in the first place, and so would be getting hit more often, resulting in a higher likelihood of the character being taken out of the combat, resulting in less damage, less effects and more combat rounds to finish the encounter.
The extra damage of the ranger will also result in an enemy dying sooner. The sooner it dies, the sooner everyone can focus on another enemy, and thus the sooner the combat is over.
You cite that we have different experiences as a reasoning behind why we're approaching this differently. However I'm not only drawing from experience. When asking questions like the OP did, one has to assume the base level of experience unless otherwise noted. Otherwise the answers are all meaningless. Therefore you have to assume 100% adherence to the rules in order to answer the question with any meaning. Sure, you can alter the system all you want to compensate for any factor, but that's not answering the question, it's bypassing it.
As for whether I use RAW when designing encounters and running games, that is a huge leap of logic to make from my comments. I have designed four separate custom 4e homebrew systems that overhaul the entire design of 4e from a ground up perspective and I have a long post history in the House Rules forum. I also run games completely on the fly with little to no preparation. Assuming I use nothing but RAW in my games based on one minor comment is drawing conclusions based on no evidence and so entirely on argumentative bias. I simply can separate between the logic required for an informative answer based on the original question and my own personal preferences.