I'm not an expert on BRP/RQ systems, but I do have some experience training with Japanese weapons of different lengths. I can see why you have some difficulty with the "reality check" aspect of this game system. The rule is trying to capture a very complex aspect of armed combat in a simple mechanic.
Every weapon has an optimum attacking distance based on its length and how it is used -- a swung sword has a different attacking distance than a thrust sword, etc. Every weapon also has different characteristics that make it "faster" or "slower" to use: A moderate length naginata with a not-too-big blade can be manuevered/swung fairly quickly while a halberd with a very large head might be very difficult to swing because of the imbalance and weight, depending on how well made it is.
The important thing about attacking distance is that an effective way to fight someone with a long weapon is, as folks have pointed out, getting inside of his attack range. This works even against swords when you have a weapon like a staff that can be used at various attack distances by "choking up" on the grip, that is, by changing your grip to "shorten" the weapon. Trying to change your grip on a sword could result in lost fingers. Quarterstaffs probably work well at this too: use the staff's full length to get inside your opponent's range, then shorten up the grip on the staff and deliver a nice crushing blow.
There were many classical fighting schools in Japan that taught grappling in armor and with weapons precisely because someone might try to get inside the range of your sword and take you down. Or you might want to do that to your opponent.
It seems to me, then, that if you wanted to have an accurate simultion of what is going on in armed combat, you should probably have a mechanic for when two people are using weapons with similar strike distances, and have mechanics for how to get inside a longer weapon's strike distance and how to get back away from someone inside your strike distance. And you need to have mechanics for grappling with weapons and in armor.
I'm not sure, however, that if you cooked up something like that that it would be worth the trouble. But it might be a good exercise just to try it.
That's my thought for the day, and it's worth at least what you've paid for it -- nothing!
Cheers,
Karl