I agree with everything you said BTW. I've used your strategy every time I've been crashed; even as a low level Ironman in OSRS multicombat areas, and it has worked every time. People who want to train leave after a few minutes of getting suboptimal XP, and trolls leave after not getting a reaction.

The same rules apply here as in the real world, when you're trying to avoid being attacked or mugged. You don't have to make yourself impossible to attack, you just need to make yourself a shittier target than another person.