As silly an example as this is, how about equipment? You can buy 2 swords. They stack. This isn't in the rules, it's just assumed.
Similarly, you can buy two Nightsticks. Whatever we might say about the effect created, there's no question the physical presence of the nightsticks stacks.
So, items stack.
It seems though, that this argument is flawed. Let's assume I couldn't find a rule that said 'generally, things stack'. Instead, the rules either say things stack, or say they don't stack. Where the rules are silent, how would we adjudicate this? We can assume that there is no rule that says that generally things stack. However, can we assume there is a rule that says they don't? If so, why?
It seems in this situation, you need to make a decision about whether things stack when the rules are silent. Is there support in the rules about which way to go for this?
Two swords do not stack. Otherwise you'd be wielding an infinite number of swords per hand.
If you cannot come up with an example that shows "unless otherwise stated, things stack", then by definition it cannot be a general rule. A general rule is one which is so common, it need not be said and can be assumed to be in effect unless otherwise stated. If you cannot even find an example of this assumption, then it is not a general rule. Heck, I would go so far as to say that if an example doesn't immediately just leap out at you when you think about this, then it cannot be a general rule.
A general rule is something like "if you throw things up, it always comes back down". Examples are so abundant that I would just toss a coin in the air to prove my point. The exception comes in when you throw something hard enough to hit escape velocity (practically impossible on Earth, but on the moon, quite possible).
You just shot yourself in the foot and torpedoed your entire argument.