There are many different styles of Jujitsu. Brazilian Jujitsu is what exposed grappling to the mainstream through the UFC, but there is a lot more to jujitsu than ground work.
I studied Miyama Ryu Jujitsu, and we had many defenses against multiple attackers. The attackers would wield knives and clubs most of the time. In our school, they didn't emphasize grappling that much at all, and it was said that thats the last place you want to end up. Multiple attacks are common in most martial arts and not special to aikido.
Correct me if I'm wrong but the multiple attacks that I have seen in aikido seem more to be about movement drills and not real attacks per se.
Thanks for answering. I should've prefaced my previous statement by saying that I don't know a whole lot about Jujitsu, and that what I think I know comes partly from general reading and partly from observing a local Brazilian Jujitsu club.
In our dojo, randori practice emphasizes movement because the emphasis in aikido is less on taking down the attacker and more on not getting hit. The ukes are still intent on grabbing or hitting nage, and nage still tries to throw them, but we teach that it's important for nage not to waste too much time dealing with one uke when there's another uke coming up from behind.
Also, most of the students in our dojo are relative beginners, so going straight into "real" attacks (with knives and clubs I presume) would be counterproductive: most of them would probably get creamed before they had a chance to learn anything. The lesson has to be geared to the skill level of the student.
If you're questioning the "reality" of the attacks used in Aikido, there are many forums on this site devoted to that topic. It seems to be pretty controversial.
Yours in ukemi,