You said, "You are right of course - you need to start somewhere (rules, definitions and tactics) but then very quickly you need to start stripping those things away."
That is so true. Traditional Randori is like an en vitro experiment. We must get past the fundamentals and then call into question tactics.
I do not know of mass attacks in the real world that do not include some form of blunt or edged weapon. And these days, someone likely has a hidden pistol in them if they are gang related.
Some ideas on tactics.
1. Go for the attacker who is wielding the most devastating weapon first. Take it from him and tactics change immediately.
2. When disarming him, the beauty of the throw is not as important as the disarm. Beware that centripetal forces are at play in big falls.
I offer these two video clips as a case in which traditional throws against an opponent wielding a pistol
May require some augmentation in technique.
Look at throw #3 and #4. in #3, I intentionally loosen my connection to the Kite gaeshi technique (something I would not normally do), in order to create a whip that disarms the pistol.
In technique #4 I am more concerned about making the perfect hiki otoshi that I forget to whip the gun away and am pulled if balance myself.
3. Another issue is to know when to revert your knowledge of a weapon's weakness. So many people get stuck performing jujitsu or Aiki against a firearm without changing traditional methods to take advantage of the firearm's weaknesses. Semi-autos jam easily. Creat a type 3 malfunction and it becomes a club at best. You as Tori should know this - the opponent may not. This buy you many options for the next move as type 3 malfunctions take time to clear.
4. Long arms work differently than handguns.