If the better skilled attacker makes the same number of attacks as the lesser skilled attacker, they are better. You want a system where a better skilled attacker who is attacking more often (thus exposing himself to risk) is still better than an attacker who is less skilled but makes just one attack.
Okay, let's look at this claim. A 20th level rogue has the same attack bonus the fighter does, presumably. They make 1 attack a round. Is the rogue
as skilled in martial combat as the fighter? Because, if we're going with the above, the answer must be yes. Given bounded accuracy, increasing the fighter's attack bonus isn't feasible within the design parameters, so how do you represent the fighter being better, more skilled even, at martial pursuits? Oh, yes, by increasing the number of attacks at that attack bonus. Your argument here is divorcing the exact class feature meant to represent more skill and moving it over into the penalty column.
Also, I didn't ignore action surge. You said 10 rounds, which with your +4 attacks per surge twice was 48 attacks, the same as I used. This was your scenario--288 attacks over a 6-day period.
You did, actually, not include the action surge attacks. I can tell because I get your numbers running 10, 20, 30, 40 at 0.01, 0.0025, 0.0025, and 0.0025 chance respectfully (9.5%, 4.8%, 7.2%, and 9.5%). Regardless, that's not very important, because the same pattern holds, if at a lower percentage due to the omission.
I did this because it is what you wanted, isn't it? You complained about the odds, and I offered ways to mitigate the odds even more. I don't need "this many saving constructions on a rule". 
No, I never asked you to reduce the percentages.
We are perfectly happy with our fumble system:
View attachment 128413
I just had our DM send me the current version we've been using for a while. I will admit, my bad: I thought you made the disaster check if you failed the fumble check, but you only roll for a disaster if the fumble check is also a nat 1.
And FYI, our current house-rules are only 2 pages. 
Here they are:
View attachment 128410
View attachment 128411
Hardly rivals the PHB, does it? 
No, it does not. I honestly expected more houserules from you given the number of houserule discussions you've started. I stand corrected.
However, I note that a lot of the problems you've come here to discuss appear self-inflicted -- half of your house rules are massive power-ups to PCs, and the other half (that hit be a crit rule, woof!) are debuffs to keep the first half in check. Not my cuppa, but, hey, if it's what you guys like, more power to you!
