That drowning rule is from a different game as are the other options I described. It is called 'Fifth Cycle' and is very, very similar to Runequest. So much so that I suspect it was written by someone who started off playing RQ. You know, like many published rpgs throughout the 80's and 90's were written by someone doing a 'better' version of D&D. Usually they have a few good ideas but otherwise are like the parent game. What have been called 'fantasy heartbreakers', which term I do not like. This particular one has great similarities to RQ and Dragonquest. Skill-based, percentile roll under, a 5% critical and 20% special, hit locations (without the hit point pool, as noted) and much more. The reason I like it (well, one reason) is a very good magic system that has everything D&D does, pretty much, melded with a RQ style combat system. And there are factors that make it fairly fast and easy to run in spite of some weaknesses (don't they all have them?).
The drowning rule example used a character with a low END. The stats run from 6 to 30 for a human. A PC is usually much better off than the poor example. Another factor is that you still get your Swim rolls every round to stop the process, albeit at a lower percentage chance. It (the save) starts at ENDx5% and falls after each failure. So it simulates someone floundering and trying to get air nicely. The process can be pretty nerve wracking to the PC's.
The lightning bolt example comes from another game yet, Legends of Yore. I have never tried to run it but I got a lot of good ideas from it that enhanced my BRP games (and Fifth Cycle) greatly.