For example, if you consider the sword, which sword school/tradition/discipline are you basing your sword work on? Then, how do integrate this into training for "Armed while facing multiple opponents"?
The specific weapon skills are best taught by a weapon school. For example, I said firearms and Aikido are highly compatible systems. That doesn't mean that Aikido is good at teaching you to use a pistol. What it means is that Aikido is a base system which teaches you to keep your weapon hand free (wrist techniques), keep you out of the clinch (body techniques) and in a good position to use your weapon (tai sabaki). The specifics of the weapon are not taught within the syllabus, but the ability to keep your weapon useful is.
This point is where many people get confused when I say that Aikido is a weapon based system. Aside from aikiken and aikijo, Aikido doesn't teach weapon specifics. Instead Aikido teaches you how to stay free from attacks that would inhibit your weapon use. If you've ever struggled over a weapon you can appreciate how important this skill is.
Also, when you say "Armed while facing multiple opponents", are the opponents armed as well?
The opponents may also be armed. But Aikido doesn't tech lot's of specifics about this. For example, if you were in a one-on-one sword fight, as I was saying, Aikido doesn't teach many of the needed skills that you may learn in say a koryu sword heavy system. However Aikido does teach us to deal with basic armed attacks: Yokomen, Shomen, Tsuki. Here is a quick video of me explaining the basics of this idea: