Sharing this old clip as this side of BJJ doesn't tends to get much airtime https://www.youtube.com/watch?v=CJQHfoGQlxI
I was led to believe that BJJ based their self defense stuff on the goshin jutsu forms of judo. I see lots of similarities. Here is a clip of some judo self defense for comparison. If you get a chance go to the part where Mifune sensei is demonstrating (starts 208) http://www.youtube.com/watch?v=dx23BoTIJ0s LFD
https://m.youtube.com/watch?v=9Bxb9N-9ZmI Here's the famous Rickson and Royler demonstration. To me, many of the SD drills, are shortcuts to victory that can be there if your opponant doesnt know how to fight. As such sometimes drilling them without resistance can lull people into a false sense of security. The GA guys break them down and do light mma type drills with them, but with preordained winners and losers. I think there's a place of such training, but I think its better after a good foundation of basics have been ingrained. Otherwise you get good at scarfhold escapes vs people who cant scarfhold, and technical get ups vs people who cant hold you down. IIRC Carsons do SD drills vs full resistance and boxing gloves regularly so that they dont loose the fighting root of the art.
Its likely the "judo plus other" that formed early BJJ formed the nucleus of the SD material, intetestingly many of these are done quite differently in the different branches of the family.