I disagree. I believe knowledge in striking is a necessity when dealing with multiple opponents. Judo has striking preserved in Kata, but without sparring it's not of much use.
Krav Maga has much better tactics for multiple opponents and armed fighting. It's sole focus is self defense, there's no sport or spiritual development involved(unless you count psychological preparation in it).
Well you're right I was thinking about judo self-defense class.
The judo based self defense class teaches striking. I guess some dojo's are different.